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The phase composition and magnetic properties of FeNi nanoparticles encapsulated in carbon with a nickel content of about 10% are studied in comparison with FeNi nanoparticles of similar composition without carbon coating. The Fe91Ni9 particles have the body centered cubic structure, whereas the Fe88Ni12@C particles have the face centered cubic (FCC) structure. The Fe88Ni12@C particles are characterized with a rather high magnetization of 60 emu g−1 in the field of 30 kOe at 5 K and 40 emu g−1 at 300 K. The monotonous behavior of magnetization with temperature gives grounds to assume that the Fe88Ni12@C particles retain the FCC structure over the entire temperature range down to 5 K. It is concluded that the stabilization of FCC phase of Fe88Ni12@C and the ferromagnetic state of this FCC phase are related to a large concentration of carbon in the core of the nanoparticles. [ABSTRACT FROM AUTHOR]

The layered perovskite compounds, which show multiferroic properties, have attracted interest due to their interesting magnetic and electronic properties. Herein, the heat capacity of EsBaCuFeO5 (Es = Ho, Gd and Yb) as a function of the temperature using the overall equation of fitting is investigated. The Debye temperature, Einstein temperature, the coefficients m and γ are derived by fitting experimental heat capacity data with the overall equation of fitting that consists of the contribution from electronic, Debye, and Einstein terms. The values of the fitting parameters obtained are in good agreement with the results in the literature. The results display that the method can be used for calculation of the heat capacity of the layered perovskite compounds over the entire range of temperature. [ABSTRACT FROM AUTHOR]

A promising strategy to tailor the magnetic and electronic properties of 2D van der Waals magnets is to integrate them with a ferroelectric (FE) substrate. Herein, the FE substrate effect of BiFeO3(0001) with different surface terminations is explored using density functional theory calculations for the ferromagnetic 2H‐VS2 monolayer. It is observed that depending on the polarization direction and surface termination of the BiFeO3(0001) FE substrate, the 2H‐VS2/BiFeO3(0001) interface exhibits a substantially varied charge transfer behavior. The magnetic and electronic properties of the monolayer 2H‐VS2 are significantly modulated by the interface charge transfer. Furthermore, in the 2H‐VS2/BiFeO3(0001) heterostructures, large interface magnetoelectric coupling coefficients are predicted. The in‐plane magnetic and electronic properties of monolayer 2H‐VS2 can be effectively tuned by the out‐of‐plane FE polarization, paving the way for a novel class of spintronic devices based on the 2H‐VS2/BiFeO3(0001) hybrid system. [ABSTRACT FROM AUTHOR]

Herein, the crystal structure, surface morphology, and magnetic and thermal properties of the BaFe11.9In0.1O19‐substituted M‐type hexaferrite are investigated. This solid solution is fabricated using "two‐step" topotactic reactions. It is determined through the X‐ray diffraction method that the crystal structure of this solid solution under normal conditions has hexagonal symmetry with P63/mmc space group (No. 194) with the unit cell parameters a = 5.8992(1) Å and c = 23.2275(7) Å. It is determined by the scanning electron microscope (SEM) researches that the average size of the grains is d¯ = 6 μm. It is determined by the vibration magnetometry that the ferrimagnet–paramagnet phase transition happens at around TC = 420 °C. Using differential scanning calorimetry (DSC), it is found that air and water molecules leave the sample surface up to 420 °C and the resulting oxygen anions appearing as a result of a solvothermal reaction fill the oxygen vacancies in the crystal structure at high temperatures up to 800 °C. The thermal transitions repeated in the high temperatures are established. The oxidation behavior of this compound is determined from thermogravimetric analysis (TGA) in a wide temperature range. [ABSTRACT FROM AUTHOR]

Diluted magnetic semiconductors (DMS) are interesting because of the interplay between the electronic and magnetic subsystems. Selected magnetic properties of IV–VI DMS are described, looking at the similarities and differences between magnetic properties of II–VI, IV–VI, and III–V DMS. The influence of the crystalline and electronic structure of the material on its magnetic properties is focused on, especially on the exchange interactions among magnetic ions. Methods of determination of the exchange parameters are described by using different experimental techniques, such as measurements of magnetic susceptibility, magnetization, and specific heat. The development in the material technology from bulk crystals to thin films and nanostructures is followed. [ABSTRACT FROM AUTHOR]

Structural and magnetic properties of NiCr1.7Fe0.3O4 nanoparticles, synthesized by a facile coprecipitation method, are examined using temperature‐dependent X‐ray diffraction, neutron scattering with XYZ polarizations, and magnetic measurements. The structural analysis demonstrates the stabilization of the cubic phase down to 200 K, followed by a low‐temperature tetragonal phase at 100 K and an orthorhombic phase below 50 K. The refined occupancies of cations demonstrate that the NiCr1.7Fe0.3O4 is a mixed spinel compound, wherein B sites are populated by ≈85% Cr3+ and ≈15% Ni2+ cations and A sites are populated by ≈70% Ni2+ and ≈30% Fe3+ cations. As a consequence, the reduction in the occupancy of Jahn–Teller active Ni2+ (triply degenerate: e4 t4) at A site is attributed to the stabilization of the cubic phase below room temperature. Temperature‐dependent magnetization and neutron scattering with XYZ polarizations measurements reveal the ferrimagnetic nature of the magnetic phase and the absence of spin‐spiral ordering in NiCr1.7Fe0.3O4 nanoparticles. Furthermore, field‐dependent magnetization measurement demonstrates an exchange bias field of ≈134.5 kA m−1 at 5 K. The training effect measurement is performed to discuss the origin of exchange bias based on different phenomenological models such as power‐law and multiexponent models. [ABSTRACT FROM AUTHOR]

Herein, nanostructured ternary Ni–Ti–B alloy synthesized by mechanical alloying from the elemental Ni, Ti, and B powders by high energy ball milling is described. The synthesized alloy of nominal composition of Ni70Ti10B20 results in the formation of a unique stable phase of Ni21Ti2B6, which happens to be stoichiometrically very close to Ni70Ti10B20 in the cubic symmetry. The synthesized alloy samples also show amorphization together with the formation of nanocrystalline phases of Ni21Ti2B6 at both early and later stages of the alloying process. Thermal analysis carried out on Ni70Ti10B20 induces crystallinity and reveals the formation of crystalline Ni–Ti–B ternary alloy, Ni21Ti2B6, above 523 K, confirming the stability of the ternary crystalline phase of the alloy. The magnetic saturation of the alloy is measured as 0.95 emu g−1 for the starting amorphous phase that increases to 9.05 emu g−1 for the crystalline phase upon annealing. Correspondingly, the coercivity value for the annealed sample is reduced to 70 Oe from 194 Oe for the amorphous phase. This is the first time that an evidence of the stable crystalline Ni–Ti–B ternary alloy is reported. [ABSTRACT FROM AUTHOR]

A nickel–indium (Ni–In) ferromagnetic alloy is successfully synthesized through a facile pulsed electrodeposition method. The composition, structure, and morphology are analyzed through atomic absorption spectroscopy (AAS), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and electron microscopy. The composition and structural analysis indicate fcc phase for the Ni43In57 and Ni63In37 alloys. The Ni–In alloy shows mixed phases when the Ni content is increased from 63 to 66 at%. Thermal analysis of the Ni63In37 results in an activation energy of 46 and 557 kJ mol−1 that can arise from the grain growth phenomena and phase transformation, respectively. Thermomagnetic studies show a Curie temperature of 340 °C for the Ni–In alloy with 63 at% Ni that also exhibits a saturation magnetization of 36 emu g−1. [ABSTRACT FROM AUTHOR]