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Yttrium Iron Garnet (YIG) ferrites, characterized by their superior magnetic and dielectric attributes, are instrumental in advancing the development of microwave devices, particularly in enhancing high-frequency performance, integration, and miniaturization. This paper synthesizes YIG ferrite materials with the composition Bi 0.6 Y 1.4-x Ca 1+x Fe 4.5-x V 0.5 Ge x O 12 (x = 0.10 to 0.50, incrementing by 0.10) through the solid-state sintering method. It delves deeply into the mechanism by which Ca2+-Ge4+ ions substitution regulates the magnetic properties of BiV-YIG. The microstructural and magnetic properties of the samples were systematically tested and analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), vibrating sample magnetometry (VSM), and TE106 perturbation method. At a substitution content of x = 0.50, the substitution of Ge4+ ions for the Fe3+ ions at the d-site transforms the material from ferrimagnetic to paramagnetic, and the saturation magnetization of the sample drops to 132.74 G. By calculating the ferromagnetic resonance (FMR) linewidth using the law of approach to saturation, the study elucidates the negative impact of low saturation magnetization on FMR linewidth. The mechanisms proposed in this paper provide theoretical and experimental bases for reducing the FMR linewidth of high dielectric constant Bi-substituted YIG, paving the way for developing high-dielectric, low-loss YIG ferrite materials for microwave devices. [ABSTRACT FROM AUTHOR]

We prepared ultrafine MnCo 2 O 4 particles using a facile sol–gel autocombustion method. The structural and vibrational characterizations confirmed the formation of a pure cubic spinel phase in as-synthesized MnCo 2 O 4 particles. The surface morphology analyses revealed the porous structure with an average particle size of 5 nm and uniform distribution of manganese (Mn), cobalt (Co), and oxygen (O) in the particles. We observed the presence of multiple valence states of Mn and Co, occupying both tetrahedral and octahedral sites, enhancing our insight into the material's electronic properties and structural configuration. Our magnetization studies unveiled a Curie Temperature (T C) of 185 K with ferrimagnetic ordering below T C , resulting in substantial magnetization (9.8 emu/g) and coercivity (3.46 kOe) at 2 K and weak magnetic behavior above T C. This is attributed to the finite size and surface effects. Furthermore, the incorporation of MnCo 2 O 4 nanoparticles and graphene oxide into a polyurethane foam matrix resulted in an excellent sound absorption coefficient of 90 % at 2000 Hz. This outstanding acoustic performance underscores the versatile applications of MnCo 2 O 4 nanoparticles in diverse noise mitigation applications. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, the ion-exchange technique in molten salts was investigated to introduce copper ions in a bioactive and ferrimagnetic devitrified glass. This approach aimed to develop a magnetic and bioactive material for oncologic bone implants, able to join the ability to promote bone bonding to hyperthermic therapy while simultaneously lowering the risk of developing post-surgery infections. The ion-exchange approach was developed in order to overcome experimental critical issues related to the influence of copper introduction as a starting reagent, during the material synthesis, on magnetite nucleation. The magnetic devitrified glass was prepared by melt and quenching route, followed by ion exchange in a mixture of molten sodium and copper nitrates, in three different Na/Cu molar ratios (20, 200, 2000). The obtained samples were analysed in terms of morphology, composition, ability to release heat, bioactivity and antibacterial properties. The results revealed that copper ion-exchange involved both sodium and calcium ions and the precipitation of few amounts of copper oxide aggregates occurred. The crystalline nature of the starting material and its ability to reach the temperature needed for hyperthermia, under exposition to an alternating magnetic field, were not affected. A bacteriostatic effect was obtained by samples with the highest copper amount and the copper doping did not affect the bioactivity of the glass ceramic. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs), which are powered by Maxwell's displacement current, have a wide range of applications, including energy harvesting and self-powered sensors. However, very little attention has been paid to the effect of the ferromagnetic medium on TENG displacement current. Herein, flexible ferrimagnetic poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF–HFP))/nickel ferrite (NiFe 2 O 4) fiber composite film based TENGs were fabricated and their performances were analysed. Highly crystalline, ferrimagnetic NiFe 2 O 4 nanofibers with high aspect ratio were prepared using electrospinning technique by systematic optimization of spinning parameters. Thereafter, the fibers were reinforced into the polymeric matrix to improve the β–phase and dielectric constant which in turn significantly enhanced the TENG performance. The β–phase enhancement in the composite films was confirmed by XRD and FTIR analysis; 77 % of the β–phase was achieved with the incorporation of NiFe 2 O 4 fiber. Morphological features were examined using SEM and AFM, which revealed more β–phase spherulite formation in the composite films. A notable increase in the dielectric properties was evidenced with the addition of NiFe 2 O 4 fibers and a maximum dielectric constant of∼26 was attained at 100 Hz. The TENG was developed using P(VDF-HFP)/NiFe 2 O 4 and nylon which generated an output voltage (V pp) and current (I pp) values of 584 V and 25 μA, respectively. Furthermore, the performance of TENG under an external magnetic field was examined, and a notable improvement in performance was observed, paving the way for the application of NiFe 2 O 4 fibers in hybrid energy harvesters and self-powered sensors. [ABSTRACT FROM AUTHOR]

We have investigated, for the first time, the hyperthermia properties, antibacterial, anticancer and antioxidant activities, as well as their toxicity, of Mn 0.25 Mg 0.25 Co 0.5 Fe 2 O 4 nanoparticles synthesized by the sol-gel auto-combustion method. X-ray diffraction results revealed a pure phase and good crystallinity of the synthesized. In addition, the Fourier transform infrared (FTIR) spectrum confirmed the formation of the crystallographic sites of the synthesized structure. In terms of morphology, scanning electron microscopy (SEM) showed that the nanoparticles were agglomerated. In addition, transmission electron microscopy (TEM) revealed that the nanoparticles had a cubic shape and a nanometric size of around 32 nm. Energy-dispersive X-ray spectroscopy (EDS) confirmed the chemical composition of the nanoparticles. With regard to magnetic properties, magnetic measurements showed almost ferrimagnetic behavior, with a saturation magnetization of 38.90 emu/g at room temperature. Hyperthermia measurements revealed relatively good heating efficiencies, with SAR value of 33W/g, good temperature rise and short time to reach magnetic hyperthermia temperature 42 °C (8 min). For biological activities the nanoparticles showed an excellent capacity to neutralize free radicals, eliminating 97% of DPPH and 95% of hydrogen peroxide. The dose of 40 mg/kg of the nanoparticles caused significant alterations in hematological and biochemical profiles. The material showed a significant effect on various bacterial strains, including Staphylococcus aureus and Bacillus subtilis. The synthesized nanoparticles also showed significant activity against various cell lines, including MCF-7 and HeLa. These results strongly suggest the promising utilization of Mn 0.25 Mg 0.25 Co 0.5 Fe 2 O 4 , in many applications as a potential candidate for magnetic-mediated hyperthermia. [ABSTRACT FROM AUTHOR]

This research is focused on designing new ceramic oxides with the spinel structure for a potential application as sensitive temperature and magnetic field sensors. In this respect, the mixtures of ferrimagnetic NiFe 2 O 4 with low-resistive Ni 0.66 Cu 0.41 Mn 1.93 O 4 semiconductor (molar coefficient α = 1 / 5 and 1 / 2) were prepared using the chemical co-precipitation technique followed by a low-temperature sintering of the cold-pressed powders. For the prepared materials, a variation of the electrical conductivity σ dc with temperature T (in the range 50 K–400 K) is quantitatively analyzed using different theoretical concepts of the charge carrier hopping transport occurring in disordered materials with strong electron-phonon interaction. It has been shown that an increase in α from 0 to 1 / 2 causes a step-like change of the dc electrical conductivity and, simultaneously, a gradual change in the magnetization M determined in the saturation state. The temperature coefficient of resistance T C R of the prepared ceramics takes the values from −0.6%/K (at 400 K) to −19.6%/K (below 100 K). The highest absolute value of the magneto-resistance coefficient M R determined at 150 K (and at magnetic field 7 T) registered for ceramic oxide with α = 1 / 2 was found to be 3.4%. [ABSTRACT FROM AUTHOR]

This research is driven by a desire to create composite films that combine the ferrimagnetic capabilities of pure and La/Nd substituted Sr 3 Co 2 Fe 24 O 41 Z-hexaferrites with the multifunctional features of ferroelectric polymers. A flexible magnetoelectric (ME) polymer composite films, with Sr 3 Co 2 Fe 24 O 41 (SF), Sr 2.85 La 0.15 Co 2 Fe 24 O 41 (SF–La) and Sr 2.85 Nd 0.15 Co 2 Fe 24 O 41 (SF-Nd) as the ferrimagnetic material and poly vinylidene fluoride-hexafluoropropylene (PH) as a ferroelectric component, were synthesized using solution casting method. In the current case, two steps have been used to synthesize ferroelectric and ferrimagnetic composites films: first, SF, SF-La and SF-Nd hexaferrite samples were synthesized using solid state reaction method and then 20% weight percentage of these hexaferrites were incorporated into the PH matrix using solution casting method to form composite film. In order to find the traces of collaborative interactions between the two phases, the structural, magnetic, and ferroelectric properties of these composite samples have been studied. The XRD data confirm the formation of SF, SF-La and SF-Nd hexaferrite dispersed in a piezoelectric copolymer PH matrix. The changes in the ferroelectric properties in different magnetic fields demonstrated the existence of ME coupling in the composite films. The inclusion of PH enhanced the magnetoelectric coupling of composite films. The maximal value of magnetoelectric coupling coefficient (α ME) observed is 0.213, 1.227, 3.403 and 9.797 mV cm−1 Oe−1 for SF, PHSF, PHSF-La and PHSF-Nd, respectively. There is approximately 46-time increase in the maximum value of magnetoelectric coupling coefficient (α ME) in PHSF-Nd (9.797 mV/cm.Oe) composites as compare to pure SF (0.213 mV/cm.Oe). [ABSTRACT FROM AUTHOR]

Fe doped Sr 2 RuMnO 6 (SRMO) double perovskites (Sr 2 RuMn 1-x Fe x O 6 , x = 0, 0.1, 0.2 and 0.3) were prepared by solid-state route. Both x-ray diffraction and Raman spectroscopy were performed to investigate the crystal structure of the synthesized double perovskites. Rietveld refinement of the x-ray diffraction patterns confirmed a phase transition from tetragonal to cubic space group as a function of doping concentration of iron. Raman spectroscopy at room temperature and group theory analysis revealed the phonon modes associated with the space group of the samples. The temperature dependent Raman spectroscopy showed an anharmonic behaviour of the phonon modes of the Fe doped SRMO samples. The temperature evolution of the phononic modes in the range of 300 K–620 K is predominantly influenced by the lattice degrees of freedom. The presence of several oxidation states Mn (2+, 3+ and 4+) and Fe (3+ and 4+) was confirmed by an X-ray photoemission spectroscopy analysis of the highest doped sample (x = 0.3). The magnetic properties measurements showed that the samples were completely paramagnetic at room temperature. The samples exhibit antiferromagnetism at very low temperatures and we conclude that they exhibit ferrimagnetic ground state in the mid temperature region. [ABSTRACT FROM AUTHOR]

In this study, a bilayer zigzag graphyne nanoribbon with RKKY interaction is described using a ferrimagnetic mixed-spin (2, 5/2) Ising model. The compensation behaviors and hysteresis characteristics of the system generated by various physical parameters, such as crystal fields of sublattices, interlayer exchange coupling and the intralayer exchange coupling are explored using Monte Carlo simulation. In the research results, we found that among the 30 possible spin configurations that may occur in the ground state of the system, only 21 spin configurations are stable. At the same time, under certain parameters, the system exhibit interesting behaviors such as compensation phenomena and multi-loop hysteresis. This can provide a theoretical reference for multi-state magnetic recording. • Ising model and Monte Carlo method were used to study the bilayer zigzag graphyne nanoribbon. • The effect of RKKY interaction on the magnetic properties of the graphyne was investigated. • The ground-state phase diagram, magnetization, magnetic susceptibility were obtained. • Phase diagrams and hysteresis loop of the system were presented. • Interesting behaviors of compensation temperatures and multi-loop hysteresis were found under certain parameters. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new manganese MOF is synthesized and fully characterized. • The MOF shows interesting ferrimagnetic behavior. • The MOF can efficiently catalyze cycloaddition of CO 2 with epoxides to cyclic carbonates. A new three-dimensional (3D) metal–organic framework (MOF) [Mn 3 (bqca) 2 (DMF) 4 ] n (1) is constructed based on a tricarboxylate ligand 2,3-di-(4-carboxyphenyl)-quinoline-6-carboxylic acid (H 3 bqca) through solvothermal reaction. The structure, composition and stability of the complex were fully characterized by single crystal X-ray diffraction, powder X-ray diffraction, infrared spectrum and thermogravimetric analysis. The results show that 1 has a 3D microporous framework and exhibits high thermal stability up to 450 ℃. Direct-current magnetic susceptibility reveals that 1 is a rare ferrimagnetic homospin system. Importantly, 1 can effectively catalyze the cycloaddition reaction of CO 2 with epoxides to generate cyclic carbonates with high yields and selectivity, and it can also be recycled at least five times without a noticeable change in catalytic efficiency. [ABSTRACT FROM AUTHOR]

A Z1-type Fe 3 Pd alloy with negative enthalpy of formation at ambient pressure has been discovered recently, however, its physical properties under high pressures remain unclear. In this work, the effect of pressure on the magnetic, electronic, lattice dynamic, mechanical and thermal properties of the Z1-Fe 3 Pd are investigated thoroughly by the first-principles methods. Under high pressures, the Z1-Fe 3 Pd are energetically favorable compared to other types Fe 3 Pd structures. A pressure-induced magnetic phase transition from ferromagnetic (FM) to ferrimagnetic (FIM) state are found, and the FM and FIM states are dynamically and mechanically stable under high pressures. The electronic density of states for both the FM and FIM states are analyzed to understand their magnetism. These two magnetic configurations are ductile, but their elastic properties and anisotropy are quite different. Additionally, the FM and FIM states have high uniaxial magnetocrystalline anisotropy, the FM state is a semi-hard magnet, and the FIM state undergoes a transition from hard magnet to semi-hard magnet with pressure. Finally, the volume and linear thermal expansion coefficients under high pressure are calculated, and the anisotropy of thermal expansion is also discussed in detail. • A stable Fe 3 Pd structure under high pressure is discovered for the first time. • The pressure-induced magnetic phase transition from ferromagnetic to ferrimagnetic state is determined. • The structural stability is verified by formation enthalpy, phonon and elastic. • Elasticity, thermal expansion and their anisotropies are investigated. • Ferrimagnetic state transforms from a hard magnet to a semi-hard magnet under high pressure. [ABSTRACT FROM AUTHOR]

The mean-field approximation based on the Gibbs-Bogoliubov inequality and Monte Carlo simulations based on the Metropolis method in the Blume–Emery–Griffiths model were used to successfully examine a hexagonal Ising nanowire with spin-1. It was found that the model displays fascinating phase diagrams in various planes of interest by using both methods. The investigation of magnetic hysteresis cycles also exhibits interesting properties. The model not only presents first- and second-order phase transition lines, but also the tricritical and isolated critical points, multi-compensation temperatures, and magnetic hysteresis behavior with one to eight cycles. • The mean-field approximation based on the Gibbs-Bogoliubov inequality is applied. • The Monte Carlo simulations based on the Metropolis method is employed. • Spin-1 Blume–Emery–Griffiths model for hexagonal Ising nanowire is investigated. • First- and second-order transitions, tricritical and isolated critical points are found. • Multi-compensation and magnetic hysteresis with one to eight cycles are observed. [ABSTRACT FROM AUTHOR]

We report here the studies of structural and magnetic properties of two equiatomic quaternary Heusler alloys CoCrVZ (Z = Al, Ga). Both the alloys crystallize in LiMgPdSn type crystal structure (space group #216) with B2 (CoCrVAl) and A2 (CoCrVGa) type anti-site disorder between elemental sites. Intended stoichiometry was confirmed from the compositional analysis. The temperature dependence of dc magnetic susceptibility and the low temperature moment values show a nearly compensating ferrimagnetic behaviour at low temperatures for both the alloys. The inverse of dc magnetic susceptibility starts to deviate from the Curie–Weiss law below 220 K and 164 K for the alloys containing Al and Ga respectively. The Arrott plots confirms the absence of long range order down to 2 K. Further analysis of the dc and ac susceptibility shows that the observed behaviour is due to the presence of Griffiths like phase in these alloys. • Systematic study shows that CoCrVZ (Z = Al, Ga) Heusler alloys crystallize in LiMgPdSn type structure (space group #216) with 50% B2 (CoCrVAl) and 25% A2 (CoCrVGa) type anti-site disorders. • The presence of disorder leads to the reduction of magnetic moment and a nearly compensated ferrimagnetic behaviour at low temperatures. • The presence of Griffiths like phase is inferred for both the alloys. [ABSTRACT FROM AUTHOR]

This study investigates the magnetocaloric potential of the Al 50 Cr 21-x Mn 17+x Co 12 (x=0, 4, 8 at%) high-entropy alloy (HEA) series using integrated experimental and theoretical approaches. Structural analysis by X-ray diffraction and scanning electron microscopy indicate a dual phase containing B2 and body-centered cubic (BCC) structures. Magnetic characterization shows an approximately linear decrease in saturation magnetization and Curie temperature with increasing Cr content. Curie temperatures calculated by Monte Carlo simulations suggest that the measured magnetic properties originate from the B2 phase rather than the BCC phase. The enhanced magnetocaloric effect with decreasing Cr content highlights the attractiveness of HEAs in magnetocaloric applications. • Al 50 Cr 21-x Mn 17+x Co 12 (x=0, 4, 8 at%) high-entropy alloys were prepared by arc melting. • The phase and chemical composition analysis indicates a dual phase containing B2 and BCC structures. • Calculated T C s suggest that the measured magnetic properties originate from the B2 phase rather than the BCC phase. • Tunable TC and magnetization with decreasing Cr were confirmed through measurement of TC and hysteresis loops. • The magnetocaloric effect was quantified by measuring the adiabatic temperature change and magnetic entropy change. [ABSTRACT FROM AUTHOR]

We investigate the ferromagnetic–ferrimagnetic ternary alloy model with the chemical formula A B p C 1 − p with mean-field theory based on Glauber-type stochastic dynamics, namely dynamic mean-field theory, on a honeycomb lattice consisting of spins S i A = 1 / 2 , S j B = 3 / 2 and S j C = 5 / 2. The model includes a selective site disorder, meaning that S i A can randomly have S j C as its nearest neighbor or S j B with probability (1 − p). The mean-field dynamic equations were obtained and numerically solved. To identify the type of dynamic phase transitions (first- or second-order), the thermal behavior of dynamic magnetizations was examined. For specified values of the crystal field parameter, exchange interaction parameter, and concentration ratio, the phase diagrams are calculated in the (d − T) and (T − h) planes. The system's fundamental and mixed-phase areas were identified. The system displayed A , T P , Q P , Z special points and dynamic tricritical points. It was found that the content of the ternary alloy continuously affected the critical temperature in our dynamic system. Reliable agreements are observed when our findings are compared to those in the literature. [Display omitted] • Magnetic properties of a Ferro-Ferrimagnetic Ternary Alloy System are investigated. • We obtained the dynamic phase transitions. • The dynamic phase diagrams are plotted on different planes. • It was observed that dynamic magnetic properties of Ternary Alloy System were strongly dependent on Hamiltonian parameters. [ABSTRACT FROM AUTHOR]

This work utilizes a multi-scale computational approach combining first-principles density functional theory (DFT) and Monte Carlo statistical simulations to provide fundamental insights into the impacts of vanadium (V) doping on the structural, electronic, magnetic, and thermodynamic properties of wurtzite zinc sulfide (ZnS). 2 × 2 × 2 ZnS supercells with controlled V doping concentrations from 12.5%–25% substituting zinc sites were constructed. The introduction of V dopants induces systematic expansions in lattice parameters and cell volume, attributed to the larger ionic radius of V 2 + than Zn 2 + , while the average compressibility shows minimal variation. However, V incorporation is found to soften ZnS by over 15% at higher dopant contents, increasing compliance and anisotropy. Stable ferromagnetic spin couplings emerge, mediated by host carriers without precipitating V secondary phases. The band structure develops half-metallic electronic properties with the lifting of spin degeneracy and preferential spin-up band metallicity induced by V-3d and S-3p hybridization effects. This results in 100% spin polarization at the Fermi level. Monte Carlo simulations based on a tight-binding Hamiltonian constructed from maximally localized Wannier functions to accurately calculate the exchange interactions between V spins successfully reproduce the magnetic phase transition behavior. The results confirm high Curie temperatures exceeding 300 K at 25% V, attributable to the significant strengthening of short-range ferromagnetic couplings over antiferromagnetic interactions. The integrated computational approach provides fundamental insights into the microscopic origin of carrier-mediated ferromagnetism in V-doped wurtzite ZnS dilute magnetic semiconductors. The systematic first-principles calculations and statistical mechanics modeling establish clear structure–property relationships linking V doping configurations and concentrations to tuned mechanical response, enhanced stability, electronic structure modifications, spin polarization, and magnetic ordering temperatures in ZnS. The results present design pathways and predictive capabilities to guide experimental efforts toward emerging high-performance magnetic materials for spintronic technologies. [Display omitted] [ABSTRACT FROM AUTHOR]

Polycrystalline samples of DyCo 9 Si 4 with the tetragonal LaFe 9 Si 4 -type structure have been synthesized by arc melting and high-temperature annealing. Results of the magnetization M and specific heat C p measurements show the existence of two magnetic anomalies at T C = 40 K and T m = 20 K. The transition at T C = 40 K is attributed to the ferromagnetic transition of the Co sublattice. The magnetic moments of Dy3+ appear to align gradually below T C , and almost fixed below T m , at which a broad maximum in C p has been observed. Field-dependent M at T = 2 K up to H = 7 T suggested that the magnetic moment of Dy3+ is coupled antiferromagnetically with those of Co, forming a ferrimagnetic structure. Magnetization measurements up to 50 T at low temperatures using a pulse magnet demonstrated a spin-flip transition around H = 20 T, above which the magnetic moments of Co and Dy are in parallel. The spin-flip transition becomes broad with increasing temperature but still remains at T C = 40 K, indicating a strong antiparallel coupling between Co and Dy moments even in the paramagnetic state. The magnetocaloric effect was evaluated from C p and M , and also from the sample-temperature variation in the quasi-adiabatic process with the pulsed magnetic field. The maximum entropy change for the field change from 5 to 0 T was observed at around T = T m with the value Δ S = 5 J/kg K. The maximum temperature of Δ S shifts to higher temperatures in high magnetic fields, resulting in the large value of Δ S = 24 J/kg K at T ∼ T C by the field change from 50 to 0 T. The present results demonstrate that the pulsed-field measurement is a powerful method to evaluate the magnetocaloric effect of materials. ● Physical properties of DyCo 9 Si 4 are reported for the first time. ● Step-like increase of the magnetization curve is observed at low temperature. ● Antiparallel coupling of Dy/Co magnetic moments remains in the paramagnetic state. ● Pulsed field measurement enables a quick and reliable magnetocaloric evaluation. ● Large magnetocaloric effect of 24 J/kg K is observed at T = 40 K. [ABSTRACT FROM AUTHOR]

Magnetic properties of multicomponent alloys depend sensitively on the degree of atomic order on the different crystallographic sites. Here we report the contrast between the magnetic properties of bulk and thin-film samples of the Heusler alloy V 2 FeAl. Arc-melted bulk ingots show no site preference of the elements (A2 structure), whereas magnetron-sputtered thin-film samples display a degree of atomic ordering with a tendency towards XA-type order. Electronic structure calculations favour ferrimagnetic XA-type order, and the effect of different pairwise atomic disorder on the element specific and net magnetic moments are evaluated to reproduce experimental observations. XA-type thin-films with iron moment of 1.24 μ B determined by X-ray magnetic circular dichroism are in agreement with calculation, but the measured net moment of 1.0 μ B per formula unit and average vanadium moment are smaller than expected from calculations. The measured Curie temperature is approximately 500 K. Films with a higher degree of disorder have a lower T C , close to 300 K, with a net moment of only 0.1 μ B at low temperature. The large calculated vanadium moments are destroyed by partial disorder on 4 d vanadium sites. By contrast, the arc-melted and annealed bulk alloy with a fully-disordered A2 structure shows no spontaneous magnetization at any temperature; it is a Pauli paramagnet with dimensionless susceptibility χ v = 2.95 × 10-4. [Display omitted] [ABSTRACT FROM AUTHOR]

Samples with inversion parameter values (δ) ranging from 0.27 to 0.14 while maintaining the crystallite size value have been successfully fabricated from commercially available powders by mechanical grinding and thermal annealing treatments at temperatures ranging between 400 and 600 °C. Detailed characterization studies of these samples using X-ray, neutron diffraction and magnetic measurements have confirmed for the first time the simultaneous coexistence at 2 K of short range antiferromagnetic and ferrimagnetic ordering for a wide range of the inversion parameter. The magnetic phase diagram obtained is different from the one previously reported, which shows at 2 K the coexistence of long range antiferromagnetic order and short range order for values of inversion parameters less than 0.1 and the presence of a ferrimagnetic order only for values of δ > 0.2. At room temperature, the Rietveld analysis of NPD patterns and the magnetization curves showed a paramagnetic behavior in the samples with δ ≤ 0.1. For the samples with higher cationic inversion, typical hysteresis curves of ferrimagnetic materials were observed and the saturation magnetization values obtained agree quite well with the net magnetic moment obtained from the Rietveld refinement of the neutron diffraction patterns. [ABSTRACT FROM AUTHOR]

In the present work, [Co (1-(x + y)) Mg x Ni y ][Cr 2 ]O 4 (CMNCr)(where, x = y = 0, 0.10, 0.20) NPs are examine in detail by using experimental results. Solution combustion method is adopted to prepare the CMNCr NPs. Experimental results were studied to understand structure (using XRD), microstructure (using SEM) and magnetic behaviour (using SQUID). The structural analysis was confirmed a single-phase spinel cubic structure with singular structural distortions associated with Mg–Ni doping and the generation of metal vacancies. SEM micrographs of all samples reveal their highly porous nature. EDS was utilized to examine the elemental analysis of the samples. The formation of spinel cubic structure without impurity were also confirmed by Fourier-transform infrared (FTIR) spectroscopy and the same tool is used to investigate the absorption bands related to the A-site and B-site. For all samples, paramagnetic phase to ferrimagnetic phase transition observed at T C and conical spiral spin order transition observed at T S. The curie temperature is found to be 98 K, 89 K, and 85 K for [Co][Cr 2 ]O 4 , [Co 0.8 Mg 0.1 Ni 0.1 ][Cr 2 ]O 4 and [Co 0.6 Mg 0.2 Ni 0.2 ][Cr 2 ]O 4 samples, respectively. The spiral transition temperature is found to be 26 K, 14 K and 8 K for [Co][Cr 2 ]O 4 , [Co 0.8 Mg 0.1 Ni 0.1 ][Cr 2 ]O 4 and [Co 0.6 Mg 0.2 Ni 0.2 ][Cr 2 ]O 4 samples, respectively. All of the samples exhibit paramagnetic behaviour above T C. The negative magnetization effect were observed in [Co 0.6 Mg 0.2 Ni 0.2 ][Cr 2 ]O 4 NPs. 20% of Mg and 20% of Ni substitution to Co site in [Co][Cr 2 ]O 4 leads to the evident magnetization reversal at the compensation temperature with an applied magnetic field of 100 Oe. The M − H loop at 10 K exhibits large coercivity due to the spiral spin ordering. This phenomenon of negative magnetization in the material results in a stable state of magnetization in the material, which has significant applications in the field of magnetic storage devices. [ABSTRACT FROM AUTHOR]

The ferrimagnetic nodal-line semiconductor Mn 3 Si 2 Te 6 , featuring a quasi-two-dimensional crystal structure, has attracted significant attention owing to its rich physical properties. Here, we systematically investigate the magnetic properties of its isostructural compound, Mn 3 Si 2 Se 6. The magnetism of this material is attributed to the Mn atoms, which exhibit antiferromagnetic interactions among the Mn atoms. The competition between antiferromagnetic exchange interactions results in an overall ferrimagnetic state, with a second-order transition from paramagnetic to ferrimagnetic occurring at 68 K. Critical exponents are derived using various common experimental techniques, including the modified Arrott plot, Kouvel-Fisher method, and critical isotherm analysis. The results indicate that the magnetism of Mn 3 Si 2 Se 6 closely aligns with the mean-field model, with critical exponents β , γ , and δ determined as 0.475(3), 1.059(3), and 3.20(1), respectively, at the critical temperature of 68.3(2) K. Moreover, the curves of the magnetic entropy change − Δ S M (T , H) exhibit a peak around T c , with − Δ S M max amounts to 4.61 (3.63) J kg−1 K−1 for H ∕∕ ab (∕∕ c) with a field change of 7 T. The estimated magnetic entropy value near T c through specific heat is remarkably saller than the expected spin entropy of Mn2+ ions, indicating the presence of short-range interactions in the paramagnetic region. • The competition exchange interactions result in an overall ferrimagnetic state in Mn 3 Si 2 Se 6. • Magnetism of Mn 3 Si 2 Se 6 aligns with the mean-field model. • Specific heat analysis reveals short-range interactions in Mn 3 Si 2 Se 6 's paramagnetic region. [ABSTRACT FROM AUTHOR]

Density Functional Theory (DFT) calculations are performed using full potential linearized augmented plane wave (FP-LAPW) method to study CoTiFeGe and Co 2 Fe 0.25 Mn 0.75- x Ti x Ge (x = 0, 0.25, 0.50, 0.75) systems through GGA and mBJ-GGA formalisms. The lattice equilibrium optimization was conducted to determine the stable magnetic phase state of these systems. It was found that the systems exhibit stability in a ferromagnetic nature, with the exception of the Co 2 Fe 0.25 Mn 0.75 Ge compound, which displays ferrimagnetic behavior. Electronic band structures and density of states for our systems show a half-metallic character using mBJ-GGA, except the Co 2 Fe 0.25 Mn 0.75 Ge system, which exhibits metallic behavior. Furthermore, the studied systems adhere to the Slater-Pauling rule condition for half-metallicity of alloys M tot = Z V -24. Optoelectronic properties have been analyzed using optical parameters, confirming semiconducting behavior. Optical reflections with minimal loss and the existence absorption are observed in the infrared and visible areas suggest that the studied systems are suitable for optoelectronic devices. Additionally, a comprehensive assessment of the thermodynamic properties of the systems was carried out to investigate their thermodynamical stability against temperature and pressure change. The transport properties of these systems were systematically investigated, revealing that our alloys present the poor thermoelectric matter. [Display omitted] • Study of thermoelectric and thermodynamic properties of two systems. • Ferromagnetic for x = 0.25, 0.50 and 0.75 and Co 2 Fe 0.25 Mn 0.75 Ge is ferrimagnetic. • Maximum spin polarization informs that the studied systems present half-metallic. • Gibbs program and are evaluated as functions of temperature at zero pressure. • Transport coefficients of the considered alloy have been investigated. [ABSTRACT FROM AUTHOR]

The contradictory relationship between magnetism and ductility restricts further applications of FeCoV alloys in high-performance electrical machines. The role of the BCC-B2 transition, accompanied by vanadium (V) site occupancies, in magnetic moments and ductility has been explored using first-principles calculations. The variations in magnetism and ductility of FeCoV alloys are attributed to the coupling of the BCC-B2 transition and V occupancies. When V replaces Fe atoms in the equiatomic B2-FeCo alloy, the superior magnetism observed in B2-Fe 50- c Co 50 V c alloys is a consequence of the enhanced local magnetic moment of Fe and the ferrimagnetic-ferromagnetic transition in the magnetic state. Moreover, due to the preferential V occupancy in the B2 phase, the B2-Fe 46 Co 50 V 4 alloy exhibits comparable ductility to the BCC-Fe 50 Co 46 V 4 alloy. The results indicate that the increased brittleness in the B2 phase arises from the raised Peierls stress and the enhanced covalent component in interatomic bonding, which is caused by the strong hybridization between Fe and Co atoms. Pearson correlation analysis illustrates that valence electron concentration (VEC) and V content are significant factors in the contradictory relationship between magnetization and ductility. The theoretical results demonstrate that tuning the V content and atomic occupancies is helpful to achieve a trade-off between magnetization and ductility in B2-FeCoV alloys. • The coupling effect of the BCC-B2 transition and V occupations on magnetic moment and ductility. • The underlying origins of magnetism-ductility contradictory relationship. • A trade-off between magnetic moment and ductility can be obtained in B2-Fe 46 Co 50 V 4 alloy. • the magnetization can be improved by adjusting VEC and V content. [ABSTRACT FROM AUTHOR]

• Ti2MnAl crystallizes with significant atomic disorder resulting in random mixing of constituent elements. • Atomic disorder plays an important role in determination of physical properties. • Ti2MnAl exhibits Pauli's paramagnetic behaviour. • Non-interacting superparamagnetic clusters emerge at low temperatures due to defects. • Disorder give rise to a negative temperature coefficient of resistivity. Search for novel spintronic materials in family of Heusler alloys has attained significant interest in recent years. In this context, Ti 2 MnAl is interesting as it is predicted to host spin gapless semiconducting state and compensated ferrimagnetic ordering. Here we report a detailed experimental investigation of Ti 2 MnAl. Our studies reveal that Ti 2 MnAl crystallizes in cubic structure with strong atomic disorder along with Pauli paramagnetic behaviour. The influence of disorder manifests in form of non-interacting superparamagnetic clusters at low temperatures and negative temperature co-efficient of resistivity. The carrier concentration obtained from Hall resistivity rules out the possibility of spin gapless semiconducting state. Our studies indicate that atomic disorder plays an important role in determination of physical properties of Ti 2 MnAl. [ABSTRACT FROM AUTHOR]

• Review on recent progress in magnetic properties of SrM magnet & it's applications. • Reviewed various synthesis processes and their effect on magnetic properties of SrM. • Covered substitutional behavior of various elements on magnetic properties of SrM. • Attempted to cover the possibility of SrM-based magnet in numerous applications. • The review paper is motivated towards an alternative to rare-earth permanent magnet. Hard magnets (HMs) are significant components in various applications like rotating machines, telecommunication, computer devices, sensors, and many more. In the HM group, permanent magnets are extensively used due to their high energy product, though they are costly and contain rare earth (RE) elements. Advancements in the magnetic properties of non-RE-based hard magnets can fulfill the technology gap between non-RE and expensive RE-based hard magnets. Hexaferrite magnets represent the largest magnet group being used nowadays by volume, in which strontium hexaferrite (SrM) is a widely used non-RE hard magnet. It is the most faithful base magnet in terms of abundance and economic balance, which requires more or less reformation and advancement in the aspect of magnetic properties. SrMs are ferrimagnetic materials, and their magnetic properties are inherently linked to the microstructures. It can be upgraded to attain high (BH) max and high curie temperature by refining its magnetic properties. Improvement in its M s and H c , even mildly, could open up the possibilities of large-scale immersion of strontium hexaferrite-based magnets in the vast field of permanent magnet applications. In the past several years, enormous improvement has been made toward enhancing the physical and magnetic properties of SrM. Identifying the synthesis parameters as well as the microstructural changes is essential for designing and improvisation of magnets. The current progress in the magnetic properties of SrM (especially high M s and high H c) by synthesis parameters and different substituting elements is briefly covered in this review, along with the applications and future aspects of Sr-hexaferrite-based magnets. [ABSTRACT FROM AUTHOR]

Development of antiferromagnetic/ferrimagnetic materials has been an area of active pursuit to advance the antiferromagnetic/ferrimagnetic spintronics. In this paper, we investigated the emergence of the spontaneous magnetization M S in the antiferromagnetic Cr 2 O 3 thin film by the Al substitution. In the case of the (Cr 1- x Al x) 2 O 3 (0001) thin films, M S increases with increasing Al composition x up to x ∼0.21. The magnitude of M S decreases abruptly for x > 0.22, accompanied with the collapse of the crystal formation. We found that the induction of the spontaneous magnetization was highly associated with the growth process. The magnitude of M S depends on the growth direction of the film: M S at 10 K for x = 0.13±0.01 is 80 kA/m, 30 kA/m and 0 kA/m for (0001), (01 1 ¯ 2) and (11 2 ¯ 0) films, respectively. The difference in M S with the growth direction is relevant to the magnetic sublattice selective substitution of Al during the thin film growth. This specific substitution occurs in the growth plane having the layer-by-layer stacking of the magnetic sublattice, which was verified by the direct observations using the scanning transmission electron microscope. [Display omitted] [ABSTRACT FROM AUTHOR]

This work used two approaches of mechanical alloying before high temperature solid state reaction to synthesize BaFe 12-x Sc x O 19 (x = 0.5 to 6.0) system. Rietveld refinement of X-ray diffraction patterns showed the formation of extra phases at higher Sc doping, along with the main magnetoplumbite structure. Raman spectroscopy suggested random distribution of Sc ions at the Fe-sites of hexaferrite structure. X-ray photoelectron spectroscopy (XPS) confirmed the +3 charge state at the Fe/Sc-sites. The Fe 3s band suggested dilution of ferromagnetic 3s-3d spin exchange interactions. The neutron diffraction study re-confirmed random occupancy of the non-magnetic Sc3+ ions at Fe3+ sites of the Sc doped Ba hexaferrite system. The transformation of magnetic spin order from collinear to non-collinear state has shown spin glass-like features at low temperature regime in the dc magnetization curves. This is an effect of dilution of Fe– O –Fe ferrimagnetic super exchange interactions and spin frustration in Sc-doped samples. [Display omitted] [ABSTRACT FROM AUTHOR]

We used Monte Carlo simulation to study the magnetic properties and compensation behavior of a ferrimagnetic mixed-spin (3 / 2 ; 1 / 2) Ising system in a graphene bilayer. The effects of exchange interactions, crystal field, external magnetic field and temperature on the total magnetization, partial magnetizations, magnetic susceptibility, phase diagram and hysteresis behavior of the system were examined. Interesting results were obtained in this work, such as the compensation behavior and the multi-loop hysteresis phenomenon for specific values of the system's physical parameters. Our results conform to those of other theoretical studies. • The compensation and critical behaviors of a Graphene Bilayer were investigated. • Different total magnetization profiles are observed in this ferrimagnetic system. • The effect of various physical parameters on hysteresis behavior was presented. [ABSTRACT FROM AUTHOR]

Using DFT and Monte Carlo simulation, we studied the physical properties of the ferrimagnetic half-metal Mn 2 RhSi Heusler alloy. Our calculations reveal a stable face-centered cubic structure without any possibility of martensitic transition. The electronic structure shows half-metallic behavior with a band gap in spin-down of 0. 49 eV calculated using PBE and 0. 85 eV using the r 2 SCAN functional, and antiferromagnetic–ferromagnetic coupling with a Curie temperature of 460 K. The elastic constants and moduli decrease with temperature due to thermal expansion, but Mn 2 RhSi retains its mechanical stability. The dominance of metallic bonds, large band gap, high Curie temperature, low magnetic moment, and good mechanical properties make Mn 2 RhSi a promising candidate for spintronic applications at room temperature. • Mn 2 RhSi is an inverse Heusler ferrimagentic half-metal. • According to the r2SCAN functional, Mn 2 RhSi has a spin-down gap of 0.85 eV. • Curie temperature of Mn 2 RhSi calculated using Monte Carlo simulation is 460 K. • Mechanical properties indicate that Mn 2 RhSi is mechanically stable and ductile over the temperature range of 0–1000K. • The wide gap and Curie temperature above room temperature suggest that Mn 2 RhSi can be suitable for spintronic applications. [ABSTRACT FROM AUTHOR]

The current work reports an unprecedented multifunctional material with optical activity and a modified magnetic response by a unique combination of doping with P and Fe into the spinel LiMn 2 O 4. Through inductively coupled plasma – optical emission spectroscopy, X-ray absorption near-edge spectroscopy, X-ray diffraction and scanning transmission electron microscopy, the chemical composition, oxidation state and the crystalline structure are determined. Solid-state UV-Vis spectroscopy, magnetic susceptibility and electronic conductivity reveal the critical importance of the interaction between iron and phosphorus when simultaneously doping the crystalline structure of LiMn 2 O 4. The presence of Fe and P considerably increases charge carrier concentration as a mechanism for enhancing electronic conductivity. Fe and P doping also creates Fe-Fe spin interactions that allow double electron optical excitations. This opens a pathway to create multifunctional materials for light-assisted charging lithium-ion batteries. P doping also induces the formation of magnetic clusters arising from the Fe-O-Fe, Fe-O-Mn and Mn-O-Mn spin exchange interactions. The magnetic response of the materials is strongly influenced by the relative amount of Fe in octahedral or tetrahedral sites of the spinel structure. Such ferrimagnetic behaviour has not been reported before LiMn 2 O 4 doped with Fe or P separately. The potential applicability of this newly identified magnetic feature was demonstrated by a significant capacity gain when a lithium-ion cell is exposed to a static external magnetic field. • Simultaneous P and Fe doping of the LiMn 2 O 4 spinel develops new ferro/ferrimagnetic properties in this material. • Phosphorous stabilizes iron-iron magnetic interactions, unseen in previous Fe doped LiMn 2 O 4. • Iron-iron magnetic interaction gives rise to double optical electron excitation and ferro/ferrimagnetic features. • Under magnetic field, ferromagnetic P and Fe doped LiMn 2 O 4 delivers higher capacity gains than other generic LIB materials. • Enhanced capacity gains occur due to an increased magnetohydrodynamic effect on the surface of the particles. [ABSTRACT FROM AUTHOR]

In this theoretical study, we investigate novel quaternary Heusler Fe–Rh–Mn–Al alloys in the X-type structure with different types of atomic ordering in the unit cell within the spin-polarized density functional calculations. The calculations showed that the 24 possible configurations converge to the 6 nonequivalent solutions. Two types of atomic ordering with the lowest total energy Fe(4c)Rh(4d)Al(4b)Mn(4a) and Mn(4c)Al(4d)Fe(4b)Rh(4a) are half-metallic ferrimagnets in which the spin polarization at the Fermi level is close to 100 %. However, no gap is open in the majority spin projection. The following values of the total magnetic moments for these alloys were obtained: 3.01 and 3.19 μ B /f.u., respectively. In the other types of atomic ordering, the half-metallic state is not formed. In FeAlRhMn, the magnetic moment on the manganese ion compensates for the moments on the other ions, and the total moment is close to zero. In the types (MnFeRhAl, AlRhFeMn) of atomic ordering with high energies, the metallic state is also realized, and the magnetic moments on the ions are ordered ferrimagnetically. In this work, we analyzed novel quaternary alloys with different types of atomic ordering motivated by the demand for alloys with a high spin polarization, among which the FeRhAlMn and MnAlFeRh alloys were found. Both with a half-metallic ferrimagnetic state and the lowest total energy among these alloys with the same chemical composition, which indicates the stability of the half-metallic state. The other types of atomic ordering are less energetically favorable, those alloys are ferrimagnetic metals with the low spin polarization. Taking into account the half-metallic state and high spin polarization, the quaternary FeRhAlMn and MnAlFeRh alloys have prospects for use in spintronic devices. [ABSTRACT FROM AUTHOR]

Mn 1.17 Co 1.83 BO 5 and Mn 1.39 Co 1.61 BO 5 ludwigites were synthesized by the flux technique and investigated by means of X-ray diffraction, X-ray fluorescence, DC and AC magnetic susceptibility, and specific heat analysis. The crystal structure of both ludwigites belongs to the Pbam space group with a = 9.25 Å , b = 12.41 Å , and c = 3.05 Å for Mn 1.17 Co 1.83 BO 5 and a = 9.27 Å , b = 12.45 Å , and c = 3.05 Å for Mn 1.39 Co 1.61 BO 5. The simultaneously observed negative values of the Curie-Weiss temperatures and ferromagnetic-type hysteresis loops allow us to assume that the ferrimagnetic ordering is realized in Mn 1.39 Co 1.61 BO 5 below T F = 60.8 K, while in Mn 1.17 Co 1.83 BO 5 in addition to the above mentioned experimental facts the frequency dependencies of the real and imaginary parts of the AC magnetization were observed assuming the presence of the canonical spin-glass state below T SG = 44.5 K. The observed difference in coercive forces of M-H curves at low temperatures can be associated with presence of two spin subsystems for Mn 1.17 Co 1.83 BO 5. • Ludwigites Mn 1.17 Co 1.83 BO 5 and Mn 1.39 Co 1.61 BO 5 has been grown using flux method and then turned to powder. • An exchange bias was observed in Mn 1.17 Co 1.83 BO 5. • Measurements show spin-glass transitions at 44.3K for Mn 1.17 Co 1.83 BO 5 and ferrimagnetic transition at 60.8K for Mn 1.39 Co 1.61 BO 5. • The effective magnetic moments per unit cell are μ eff = 8.06 μ B for Mn 1.17 Co 1.83 BO 5 and μ eff = 9.03 μ B for Mn 1.39 Co 1.61 BO 5. • Co3+ ions taking 0.38 of 3 + position for Mn 1.17 Co 1.83 BO 5 and completely fill 3 + position for Mn 1.39 Co 1.61 BO 5. [ABSTRACT FROM AUTHOR]

The current theoretical study explores the physical properties of quaternary Heusler ferrimagnetic semiconductors, specifically CrVTiAl, CrVZrAl, and CrVHfAl. Using first-principles calculations, we conduct a comprehensive analysis of the structural, electronic, and thermoelectric properties at different temperatures (300 K , 600 K , and 900 K) employing the r 2 SCAN functional. Furthermore, we investigate the impact of various types of doping on thermoelectric performance and efficiency of these Heusler compounds. Our results demonstrate the tunability of the thermoelectric properties of these Heusler compounds, emphasizing the critical role of carrier concentration, and provide valuable insights for the design and improvement of thermoelectric properties for thermoelectric applications. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The electronic, magnetic, and optical properties of MnFe 2 O 4 are studied through first-principles calculations. • The intricate chemical interactions of Mn-O and Fe-O bonds grounded in the multi-orbital hybridizations are thoroughly investigated in this article. • The optical properties, with a particular focus on prominent peaks that exhibit direct correlations with band transitions and spin configurations are an appealing research. • Various computational methods, encompassing local-density approximations (LDA), LDA + U, Perdew, Burke, Ernzerhof (PBE), and PBE + U, are considered to compare the electronic band gap and magnetic moments of MnFe 2 O 4. MnFe 2 O 4 represents a notable spinel ferrite material that synergistically combines the benefits of both Fe- and Mn-based materials. This compound emerges as a potential candidate for diverse applications encompassing biomedical techniques like thermotherapy, energy storage mechanisms such as lithium-ion batteries and supercapacitors, and advancements in optoelectronics and optical devices. Comprehensive first-principles calculations have been employed to delve into the structural, electronic, magnetic, and optical properties of MnFe 2 O 4. The intricate chemical interaction of Mn-O and Fe-O is elucidated via charge and spin features. This study meticulously examines distinct energy bands, spatial charge distributions, specific van Hove singularities, and configurations separated by spin orientation. Preliminary findings categorize the material as a semiconductor exhibiting ferrimagnetic traits. Among the computational methodologies utilized, including local-density approximations (LDA), LDA + U, Perdew, Burke, Ernzerhof (PBE), and PBE + U, the latter method shows a band gap of 1.017 eV, in contrast to the narrower gaps identified by alternative approaches. Crucially, the pronounced multi-orbital interactions spanning [4s, 3 d x 2 - y 2 , 3d xy , 3d yz , 3d xz , 3 d z 2 ] and [2s, 2p x , 2p y , 2p z ] offer insights into the fundamental physicochemical interactions of Fe-O and Mn-O. This article also presents and deliberates on the optical properties, emphasizing peaks that correlate directly with band structures and spin configurations. [ABSTRACT FROM AUTHOR]

Ab initio calculations are used in the present study to analyze the structural, magnetoelectronic, mechanical, thermal, thermoelectric, optical and thermodynamic properties of AMnBi 2 compounds (where A = Ca and Sr). The calculations use the density functional theory involving the Full Potential –Linearized Augmented Plane. Wave and the Monte Carlo simulation. We have used the Generalized Gradient Approximation (GGA) with Perdew-Burke-Ernzerhof (PBE) functional for modelling the exchange-correlation potential with Hubbard correction (GGA + U) was employed. The bulk modulus, its first derivative, and the optimal lattice parameters have been found. Both compounds display metallic nature. The electronic transport coefficients have been calculated. The entropy, thermal expansion coefficient, Debye temperature, and heat capacities C v and C p are calculated. The elastic constants at zero pressure, the bulk modulus B, and the shear modulus G have been evaluated. The Young's modulus and Poisson's ratio of two compounds have been performed. The Debye temperature is also approximated from the average sound velocity. The Néel temperature, magnetization, and hysteresis cycles are found. [ABSTRACT FROM AUTHOR]

In this study, SiCp(CNT) hybrid reinforcements were prepared by in-situ growth of CNTs on the SiCp surface by chemical vapor deposition (CVD) process. The yield strength (YS) and ultimate tensile strength (UTS) of SiCp(CNT)/7075Al were significantly improved by compensating Mg into the SiCp(CNT)/7075Al composites. The results showed that the SiCp(0.5CNT)/7075Al–Mg composites exhibited the best balance of strength and ductility at a Mg compensation of 1.0 wt %, not only the UTS (∼651 MPa) was higher than that of SiCp/7075Al-1.0 Mg, but also the elongation (3.5 %) was improved by more than 20 %. This is attributed to the fact that the Mg compensation can effectively improve the aging precipitation behavior of the interfacial micro-zones of SiCp(CNT)/7075Al–Mg, allowing it to be effectively strengthened and thus to transfer the load adequately and give full play to the strengthening effect of the SiCp(CNT) hybrid reinforcement. In addition, the toughness of the SiCp(CNT)/7075Al composites was significantly higher than that of SiCp/7075Al with or without the compensation of Mg. Further studies showed that the toughening mechanism of CNTs is divided into the following three main points: (1) the introduction of CNTs can effectively strengthens the interfacial micro-zones, thus retarding the crack initiation. And CNTs can redirect the motion of cracks through the initiation of daughter cracks; (2) the bridging, pull-out and fracture of CNTs can cause the composites to consume more energy during deformation; (3) the introduction of CNTs can effectively prolong the crack propagation path and make the deformation around SiCp more uniform. • The compensation of Mg can effectively improve the mechanical properties of SiCp(CNT)/7075Al composites. The SiCp(0.5CNT)/7075Al-1.0Mg composite exhibited the best balance of ultimate tensile strength (UTS) and ductility, with not only higher UTS than SiCp/7075Al-1.0Mg, but also an elongation increases of more than 20%. • The yield strength (YS) and UTS of SiCp(0.5CNT)/7075Al-1.0Mg composites were improved by 17.5% and 12.1%, respectively, compared to SiCp(0.5CNT)/7075Al. This is attributed to the fact that the compensation of Mg significantly improves the aging precipitation behavior near the interface and enhances the density of the η′-phases within the interfacial micro-zones. • The toughening mechanism of CNTs is mainly attributed to the following three points: (1) the introduction of CNTs can effectively retard the initiation of cracks and redirect the motion of cracks; (2) the bridging, pull-out of CNTs can effectively restrain the rapid crack propagation; (3) the introduction of CNTs can effectively prolong the crack expansion path and restrain the coarsening of cracks. [ABSTRACT FROM AUTHOR]

The influence of external pressures on the structural and magnetic properties of the FeNi alloy is elucidated using density functional theory (DFT) and Monte Carlo simulation. Utilizing a range of pressures, the study showcases compressive behavior in lattice constants, with both a and c exhibiting reductions. A sharp decline in magnetic moments is recorded at a critical pressure of 54 GPa. Indicating a magnetic phase transition from ferro to paramagnetic phase. Beyond this critical pressure, dynamical instability becomes evident, attributable to the aforementioned magnetic phase transition. Further examination of exchange interaction parameters reveals that while Fe–Fe interactions exhibited a consistent decrease with pressure, the FeNi and NiNi interactions remained relatively stable across the examined pressure range. At pressures close to 0 GPa, the Curie temperature (T C) was found to be around 838 K. As the external pressure is applied, a consequential decline in T C is witnessed, suggesting a significant sensitivity of the magnetic phase transition to external pressures. In particular, this study indicates that the FeNi alloy is sensitive to external pressures, emphasizing some relation between structural and magnetic properties. [Display omitted] • A comprehensive examination of the influence of external pressure on the properties of the FeNi alloy has been conducted. • A magnetic phase transition from a ferromagnetic to a paramagnetic state has been observed at a critical pressure of 54 GPa. • There is a decrease in the Curie temperature as the applied external pressure is increased. [ABSTRACT FROM AUTHOR]

Cobalt ferrite (CoFe 2 O 4) nanoparticles have been synthesized using two different wet-chemical methods: co-precipitation and solvothermal. Mesoporous cobalt ferrite nanoparticles were prepared using the co-precipitation method with 4, 6, and 8 wt% of Pluronic P123 and with the solvothermal method with 10, 15, and 20 wt% of PEG-4000. X-ray diffractometry confirmed the formation of a single-phase spinel structure. The saturation magnetization of the nanoparticles increased from 48 to 64 emu/g as the P123 concentration increased from 4 to 8 % wt, and decreased from 72 to 62 emu/g as the PEG-4000 concentration increased from 10 to 20 % wt. Generally, the samples synthesized by the solvothermal method had a higher specific surface area than those prepared by the co-precipitation method. In comparison to other samples, the 10 % PEG-4000 sample had the highest specific surface area and showed the highest level of dye degradation (93 %). The findings demonstrated that the concentration of Pluronic P123 and PEG-4000 had an impact on the saturation magnetization and specific surface area of the nanoparticles. [Display omitted] • Pure CoFe2O4 was successfully synthesized utilizing two separate chemical processes: solvothermal and co-precipitation. • The microstructure of the cobalt ferrite nanoparticles produced by both procedures is spherical and porous. • The solvothermal method yielded samples with a larger specific surface area than the co-precipitation method. • The magnetic properties in the system rises as P123 grows and falls as PEG-4000 increases. • Cobalt ferrite nanoparticles were ferrimagnetic, with saturation magnetization ranging from 42 to 72 emu/g. [ABSTRACT FROM AUTHOR]

The flow behavior, dynamic recrystallization (DRX), and microstructure evolution during the hot deformation of a newly developed 15Cr-30Ni-2Ti-3Cu valve alloy were studied. A constitutive model after strain compensation was established to predict the flow behavior of the alloy. A DRX kinetic model was proposed to predict dynamic recrystallization behavior during hot deformation. Both the fraction of DRX and the recrystallized grain size increases as the deformation temperature is increased from 950 ℃ to 1150 ℃, and decreases with increasing the strain rate from 0.01 s−1 to 10 s−1. A complete recrystallization structure of the alloy is obtained at the hot deformation temperature of 1150 ℃ and the strain rates smaller than 0.1 s−1. The optimal processing parameters of the valve alloy are determined as 1050 ℃− 1150 ℃/0.01 s−1-0.1 s−1. The Laves phase and (Ti,Nb)C particles precipitate during hot deformation, and hinder the dynamic recrystallization process by pinning dislocations and grain boundaries. Fine γ' particles provide nucleation sites for the formation of dynamically recrystallized grains due to its ordered cubic L1 2 structure. • Arrhenius-type constitutive model and dynamic recrystallization kinetics model was established. • The hot working processing map was established to determine the optimal hot working window. • The evolution of microstructure and precipitated phase during hot deformation were studied. • The DRX microstructure were analyzed by EBSD. [ABSTRACT FROM AUTHOR]

• The Ta/GdFeCo/Ta heterostructures are utilized to achieve a spin–orbit torque-driven multistate magnetization switching. • The switching ratio is up to 47.7% and the β DL and β FL are estimated as 85.64 Oe/(107 A/cm−2) and 35.05 Oe/(107 A/cm−2), respectively. • The findings establish that a stable four-resistor state exists, proofing multilevel memory behaviors and synaptic plasticity under current drive. • Neuromorphic computing built from this SOT device can perform unsupervised handwritten digit recognition with an accuracy of 92.25%. Neuromorphic computation of ferrimagnetic materials as artificial synapses is essential for the development of ultra-low power spintronic devices. Here, Ta/GdFeCo/Ta heterostructures are utilized to achieve a spin–orbit torque-driven multistate magnetization switching, complying with the requirements of neuromorphic computation. For Ta/GdFeCo/Ta device, the switching ratio is up to 47.7 % when the critical current density value is 1.26 × 107 A/cm2. Moreover, the β DL and β FL are estimated as 85.64 Oe/(107 A/cm−2) and 35.05 Oe/(107 A/cm−2), respectively. Subsequently, the findings establish that a stable four-resistor state exists, proofing multilevel memory behaviors and synaptic plasticity under current drive. It is further demonstrated that neuromorphic computing built from this SOT device can perform unsupervised handwritten digit recognition with an accuracy of 92.25 %. This research highlights the potential of SOT-driven multi-energy stabilized residual states for neuromorphic computing and multi-energy storage in the future. [ABSTRACT FROM AUTHOR]

• Gd-content gradients influence PMA in both "+δ" and "−δ" samples. • "+δ" has lower H C due to closer T comp , suggesting different Gd-content. • Reversal of AHE loop near T comp indicates sublattice dominance shift. • Decrease in H SF suggests weakened exchange interaction near T comp. • Strong ΔR XY at ± 4 kOe and ± 30 kOe for "−δ" indicates enhanced PMA. Ferrimagnetic rare-earth (RE) – transition-metal (TM) alloys are considered small ferromagnets with antiferromagnetic exchange in sublattices, which makes them a preferable choice for future ultrafast memory-related applications. Here, we explore the magnetic properties of two GdFeCo thin films with tailored vertical composition gradients, achieved by gradually varying Gd concentration across the film thickness. The temperature-dependent magnetic behavior of these films is investigated using anomalous Hall effect (AHE) measurements and SQUID magnetometry. Both films exhibit perpendicular magnetic anisotropy with distinct coercivities, indicating variations in their magnetic properties. The films show RE-dominant behavior at 300 K. Moreover, for the positive composition gradient (+δ) film, the compensation temperature is around 350 K, while the film with a negative gradient (−δ) exhibits a compensation temperature above 400 K. Furthermore, the spin-flop behavior and AHE sign reversal provide insights into the sublattice dominance and exchange interactions within the films. The magnitude of ΔR XY (the difference in AHE resistance at different magnetic fields) is shown to be sensitive to the composition gradient, indicating stronger perpendicular magnetic anisotropy for the "−δ" sample. This study demonstrates the potential of composition engineering to tailor the magnetic characteristics of ferrimagnetic materials for specific spintronics applications. [ABSTRACT FROM AUTHOR]

Exploring valley-contrasting physics in scarce intrinsic high-temperature ferromagnetic semiconductors with feasible synthesis route is of great significance for ever-evolving moden information technology. By first-principles calculations, the TiInTe 3 monolayer is predicted to demonstrate excellent structural stability and easy-plane semiconducting ferromagnetism arising from indirect superexchange mechanism. Monte Carlo simulations based on the Heisenberg model reveal a magnetic phase transition at 583 K well above room temperature. Due to the inversion and time-reversal asymmetries, tunable valley polarization in the conduction band up to 110 meV can be achieved by varying the magnetization orientation, which is further validated by a first-order perturbation theory. More excitingly, electron doping for realizing the anomalous valley Hall effect gives rise to an out-of-plane preference for magnetization in the TiInTe 3 monolayer and thus generates spontaneous and larger valley polarizations. After doping, the ferromagnetism above room temperature remains robust in the experimentally attainable electron density regime. Our findings highlight that the TiInTe 3 monolayer is a promising ferrovalley material for developing high-performance spintronic and valleytronic nanodevices. [Display omitted] [ABSTRACT FROM AUTHOR]

Copper-containing ferrimagnetic glass-ceramic with the following composition: 24.7% SiO 2 -8.5% CaO-13.5% Na 2 O-3.3% P 2 O 5 -31% Fe 2 O 3 -14% FeO–5CuO (wt%) was synthesized by means melt and quenching process both in powder and bulk form. The obtained samples were characterized and compared by means morphological, compositional and structural analyses. The magnetic properties and the ability to release heat were also investigated together with the antimicrobial properties towards S. aureus strain. The obtained results showed that copper introduction and the annealing process influenced the nucleation of crystalline phases; in particular the samples produced in powder form evidenced a low amount of magnetite and thus a reduced hysteresis area and ability to produce heat when exposed to an alternating magnetic field. While Cu-containing samples in the bulk form maintained the magnetic and calorimetric properties of pristine glass-ceramic. Preliminary evaluation of antibacterial properties demonstrated Cu-doped samples were not able to reduce the bacterial proliferation and thus the need to optimize the copper introduction process. [ABSTRACT FROM AUTHOR]

Structural, magnetic, and optical properties along with N 2 absorption-desorption features of Sm3+–Dy3+ ions co-substituted BaSr hexaferrite microspheres (HFMSs) engineered through a hydrothermal gel approach were investigated. The microstructural and morphological features were examined by powder X-ray diffraction (XRD), surface area and pore size distribution (BET), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HR-TEM), and transmission electron microscopy (TEM) techniques. Rietveld analysis proved the purity of products. The BET revealed a slight variation in textural characteristics with increasing Sm3+–Dy3+ substitution. The surface area (11–16 m2/g) exhibits a pore volume of ~0.07 cm3/g and average pore size distributions of 26.6 nm. The 300 K and 10 K field-dependent hysteresis loops were registered. Remanent magnetizations (M r) and coercive fields (H C) are in a range of 29.15–34.05 emu/g and 1420–5391 Oe at 300 K, respectively. The estimated saturation magnetizations (M s) vary between 53.22 emu/g and 71.08 emu/g, and magneton numbers (n B) are in a range of 10.51–13.93 μ B. At 10 K, the M r = 35.18–46.83 emu/g, H C = 1487–4760 Oe, M s = 81.82–99.17 emu/g, and n B = 14.83–19.44 μ B , which are greatly higher compared to room temperature. All magnetic parameters exhibit strong ferrimagnetic features of pristine Sr 0 · 5 Ba 0 · 5 Fe 12 O 19 and Dy3+ and Sm3+ co-doped HFMSs at both temperatures. Squareness ratios (SQRs), which are very close to 0.50 assign the single domain uniaxially symmetric structured HFMSs. δ M type of remanence plots was applied to specify the intensity and type of interparticle interactions as a function of the externally magnetic field, H. The Schuster-Kubelka-Munk theory provides to estimate direct energy band gaps (E g). Undoped or co-doped HFMSs have a very narrow magnitude of E g data between 1.795 and 1.865 eV depending on the couple ion concentrations. [ABSTRACT FROM AUTHOR]

This review aims to summarize more than 100 years of research on spinel compounds, mainly focusing on the progress in understanding their magnetic, electronic, and polar properties during the last two decades. Over the years, more than 200 different spinels, with the general formula AB 2 X 4 , were identified or synthesized in polycrystalline or single-crystalline form. Many spinel compounds are magnetic insulators or semiconductors; however, a number of spinel-type metals exists including superconductors and some rare examples of d -derived heavy-fermion compounds. In the early days, they gained importance as ferrimagnetic or even ferromagnetic insulators with relatively high saturation magnetization and high ordering temperatures, with magnetite being the first magnetic mineral known to mankind. From a technological point of view, spinel-type ferrites with the combination of high electrical resistance, large magnetization, and high magnetic ordering temperature made them promising candidates for many applications. However, spinels are also known as beautiful gemstones, with the famous "Black Prince's Ruby" in the front centre of the Imperial State Crown. In addition, spinels are important for the earth tectonics, and the detection of magnetite in a Martian meteorite even led to the speculation of life on Mars. However, most importantly in the perspective of this review, spinels played an outstanding role in the development of concepts of magnetism, in testing and verifying the fundamentals of magnetic exchange, in understanding orbital-ordering and charge-ordering phenomena including metal-to-insulator transitions, in developing the concepts of magnetic frustration, in establishing the importance of spin–lattice coupling, and in many other aspects. The still mysterious Verwey transition in magnetite was one of the very first illuminating examples of this complexity, which results from the fact that some ions can exist in different valence states in spinels, even at a given sublattice. In addition, the A -site as well as the B -site cations in the spinel structure form lattices prone to strong frustration effects resulting in exotic ground-state properties. The A -site ions are arranged in a diamond lattice. This bipartite lattice shows highly unusual ground states due to bond-order frustration, with a strength depending on the ratio of inter- to intra-sublattice exchange interactions of the two interpenetrating face-centred cubic lattices. The occurrence of a spiral spin-liquid state in some spinels is an enlightening example. Very recently, even a meron (half-skyrmion) spin structure was identified in MnSc 2 S 4 at moderate external magnetic fields. In case the A -site cation is Jahn–Teller active, additional entanglements of spin and orbital degrees of freedom appear, which can give rise to a spin–orbital liquid or an orbital glass state. In systems with such a strong entanglement, the occurrence of a new class of excitations – spin–orbitons – has been reported. The B -site cations form a pyrochlore lattice, one of the strongest contenders of frustration in three dimensions. A highly degenerate ground state with residual zero-point entropy and short-range spin ordering according to the ice rules is one of the fascinating consequences, which is known already for more than 50 years. At low temperatures, in B -site spinels the occurrence of spin molecules has been reported, strongly coupled spin entities, e.g., hexamers, with accompanying exotic excitations. A spin-driven Jahn–Teller effect is a further possibility to release magnetic frustration. This phenomenon has been tested in detail in a variety of spinel compounds. In addition, in spinels with both cation lattices carrying magnetic moments, competing magnetic exchange interactions become important, yielding ground states like the time-honoured triangular Yafet–Kittel structure. Very recently, it was found that under external magnetic fields this triangular structure evolves into very complex spin orders, which can be mapped on spin super-liquid and spin super-solid phases. In addition, due to magnetic frustration, competing interactions, and coupling to the lattice, very robust magnetization plateaus appear in a variety of spinel compounds as function of an external magnetic field. Furthermore, spinels gained considerable importance in elucidating the complex physics driven by the interplay of spin, charge, orbital, and lattice degrees of freedom in materials with partly filled d shells. This entanglement of the internal degrees of freedom supports an exceptionally rich variety of phase transitions and complex ground states, in many cases with emerging functionalities. It also makes these materials extremely susceptible to temperature, pressure, or external magnetic and electric fields, an important prerequisite to realize technological applications. Finally, yet importantly, there exists a long-standing dispute about the possibility of a polar ground state in spinels, despite their reported overall cubic symmetry. Indeed, recently a number of multiferroic spinels were identified, including multiferroic spin super-liquid and spin super-solid phases. The spinels also belong to the rare examples of multiferroics, where vector chirality alone drives long-range ferroelectric order. In addition, a variety of spinel compounds were investigated up to very high pressures up to 40 GPa and in high magnetic fields up to 100 T, revealing complex (p , T) and (H , T)-phase diagrams. • Ground-breaking concepts in magnetism were developed conceptually using spinel compounds. • Spinels are prototypical examples of strongly frustrated magnets. • Ferroelectricity and multiferroicity in spinels result from very different mechanisms. • Spinels represent outstanding examples of metal-to-insulator transitions and charge order. • Examples of well-established d -derived heavy-fermion​ behaviour. [ABSTRACT FROM AUTHOR]

The physical properties of the double perovskite A 2 BB'O 6 are closely related to the B-site cationic arrangement, which directly affects the crystal morphology, magnetic coupling and electronic structure. Herein, the impact of B-site antisite defects on the magnetic and electronic properties of double perovskite Pb 2 FeOsO 6 has been investigated using spin-polarized first-principles calculations. Our calculations demonstrate that B-site ordered Pb 2 FeOsO 6 is a ferrimagnetic semiconductor with the saturated magnetic moment of ~2.27 μ B f.u.−1, mainly generated from B-site Fe and B′-site Os antiferromagnetic coupling. With the introduction of B-site antisite defects, the crystal lattices nearly maintain the original structure of the ordered Pb 2 FeOsO 6 , although the internal atomic arrangements are reconstructed. Nevertheless, the saturated magnetic moment is sharply reduced in Fe/Os disordered configurations, which originates from the additional Os–Os and Fe–Fe antiferromagnetic coupling, and consequently induces Os–Os, Os–Fe and Fe–Fe spins interaction competition. Further electronic structure analyses indicate that the B-site antisite defects do not alter the semiconducting performance of Pb 2 FeOsO 6. Our study sharpens the understanding of the effects of cationic ordering on the physical properties of double perovskites and provides an alternative avenue for tailoring their characteristics. This work illustrates the nonnegligible effect of B-site atomic disorder on the atomic distribution, spin interaction arrangements and electronic transport properties in double perovskite Pb 2 FeOsO 6. Image 1 [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel porous aggregates of multi-element doped Fe 3 O 4 /(Fe,Co, Ni, Cu) alloys (DF/alloys) composite with magnetic/magnetic heterostructure was prepared. • Ferrimagnetic spinel compounding with ferromagnetic four element alloys enlarged the M s and helped to break the Snoek′s limit. • The abundant defects and heterogeneous interfaces of the DF/alloys composite enhanced its dipole polarization and interfacial polarization and optimized impedance matching. • The maximum effective absorption bandwidth (EAB max) and minimum reflection loss (RL min) were 6.4 GHz and −49.3 dB with a thickness of 2.0 mm. Pure magnetic materials always exhibit mediocre microwave absorption performance due to the poor impedance matching and negligible dielectric loss capability. In this study, a novel porous aggregates of multi-element doped Fe 3 O 4 /(Fe, Co, Ni, Cu) alloys (denoted as DF/alloys) composite which is composed of magnetic/magnetic heterostructure with excellent microwave absorption performance were prepared. By reducing part of the ferrimagnetic spinel into ferromagnetic alloy, the saturation magnetization M s was enlarged which is beneficial to exceeding the Snoek′s limit, and the magnetic loss capability was further enhanced significantly. Furthermore, the abundant heterogeneous interfaces in the DF/alloys composites have greatly improved the dielectric loss capability and balanced the complex permittivity and the complex permeability, and achieved superior impedance matching of the magnetic/magnetic heterogeneous DF/alloys composites. When the loading ratio (DF/alloys to paraffin mass ratio) was only 30 wt%, the widest effective absorption bandwidth (EAB) reached 5.58 GHz (3.2 mm). when the loading ratio was up to 50 wt%, the widest EAB (6.4 GHz) was achieved at 2.0 mm and the minimum reflection loss (RL min) reached −49.3 dB at 4.15 GHz. As microwave absorption materials, the DF/alloys composites are extremely promising and competitive. [ABSTRACT FROM AUTHOR]

• YFeO 3 have been studied with GGA and GGA+U reveal a semi-conductor and an Antiferromagnetic type-G behavior. • Magnetic anisotropy results for both approximations show that easy axis magnetization for YFeO 3 is along the c-axis. • Evaluation of the electric polarization and the magnetic transition temperature of the orthorhombic YFeO 3 has done. In this study, we have thoroughly investigated the electronic, magnetic, and electrical properties of yttrium orthoferrite using density functional theory (DFT) within the generalized gradient approximation (GGA) and the (GGA + U) approach, which incorporates the Hubbard term (U). Both approximations consistently reveal a semiconductor behavior and an antiferromagnetic behavior of type-G between the iron (Fe) ions. To delve deeper into the magnetic interactions within YFeO 3 , we have proposed a physical model. This model allows us to calculate the magnetic exchange coupling and magnetic anisotropy parameters through DFT calculations. Additionally, we have conducted computations to determine the electric polarization. Our results have shown that the electric polarization in YFeO 3 is exclusively derived from electronic polarization. We have also explored the relationship between the direction of electric polarization and the easy-axis magnetization. In our investigation, we found that both the electric polarization and easy-axis magnetization align along the c-axis in both approximations. Furthermore, we have examined the influence of the Hubbard term on the direction of polarization. To assess the magnetic temperature transition, we employed Monte Carlo simulations using the Ising model. The critical temperature, denoted as T N , obtained with the GGA approximation is found to be 726.66 K. Remarkably, this value closely matches the experimental critical temperature when compared to the critical temperature obtained with the GGA + U approximation. [ABSTRACT FROM AUTHOR]

ZrMnSi and HfMnSi half Heusler alloys with magnetic ground state are investigated through density functional theory. The different exchange–correlation functionals (GGA, LDA, PBESol and WC) are used to study these alloys. The equilibrium lattice constants and corresponding ground state energies are calculated using these four approximation methods. From GGA functional, the obtained band gap for ZrMnSi is 1.268 eV and HfMnSi is 1.311 eV. The reported alloys are predicted to be half metals from different potentials, where those alloys show semiconductor character in minority spin channel and also exhibit metallic character in majority spin channel. The studied alloys are mechanically stable and ductile in nature. The total magnetic moment of −3 μ B is obtained in the reported ferrimagnetic alloys. The obtained thermoelectric figure of merit for ZrMnSi and HfMnSi is 0.46 at 1200 K and 0.31 at 1200 K respectively, it shows that these alloys are the potential candidates for waste heat recovery application, and they are also useful for spin flip device application. • We studied the spintronic and thermoelectric properties of the ZrMnSi and HfMnSi. • We predicted the semiconductor character of the Heusler alloys ZrMnSi and HfMnSi. • For both of the Heusler alloys ZrMnSi and HfMnSi the band gap value is 1.29 eV. • The ZT is 0.46 and 0.31 for ZrMnSi and HfMnSi at 1200 K. • ZrMnSi and HfMnSi are best suit for spintronic and thermoelectric applications. [ABSTRACT FROM AUTHOR]

Crystal structure, magnetostriction, magnetic and magnetothermal properties have been studied for novel non-stoichiometric ErFe 2 Mn x (0 ≤ x ≤ 0.6) compounds. It has been found that for х ≤ 0.4 the compounds crystallize with MgCu 2 -type structure. Curie temperature and magnetic moment values decrease with manganese alloying. Molecular field coefficients have been calculated within ferrimagnetic two-sublattice molecular field model. Magnetic and heat capacity measurements have been used to calculate magnetocaloric effect in a wide temperature range. It has been demonstrated that increasing the Mn content in ErFe 2 Mn x leads to a significant increase (up to 39 %) of anisotropic magnetostriction value at 77 K in magnetic field of 18 kOe. At the same time, the value of effective magnetocrystalline anisotropy decreases. Thus, manganese alloying opens new way for tuning magnetocrystalline anisotropy and magnetostriction in Laves phase compounds. [Display omitted] • single phase non-stoichiometric ErFe 2 Mn х compounds are formed up to Mn concentration x = 0.4. • ErFe 2 Mn х compounds with x ≤ 0.2 have the compensation temperatures at М (Т) curves. • Curie temperature and magnetic moment values decrease with manganese alloying. • The value of anisotropic magnetostriction significant increase with increasing the Mn content. • The value of effective magnetocrystalline anisotropy decreases with increasing the Mn content. [ABSTRACT FROM AUTHOR]