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In this work, phase transition temperatures of La–Fe and Ce–Fe alloys were determined using differential thermal analysis (DTA), while phase transition temperatures, microstructure, and phase compositions of La–Ce–Fe and Ce-Nd-Fe alloys were studied using DTA and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). Based on the available experimental data reported in the literature and the experimental results determined in this work, the La–Fe and Ce–Fe systems were re-assessed thermodynamically using the CALPHAD (CALcuation of PHAse Diagrams) method, and then the Ce–La–Fe and Ce-Nd-Fe systems were calculated by combining the re-assessed La–Fe and Ce–Fe systems with the previously assessed Nd–Fe, Ce–La, and Ce–Nd systems. The calculated phase diagrams and thermodynamic properties of the La–Fe and Ce–Fe systems are consistent with the experimental data. The calculated isothermal sections and vertical sections in the Ce–La–Fe and Ce-Nd-Fe systems are in good agreement with the experimental results. The solidification behaviors of Ce–La–Fe and Ce-Nd-Fe as-cast alloys were analyzed through the experimental examination and thermodynamic calculation with Scheil-Gulliver non-equilibrium model. The simulated results agree well with the experimental results. It indicates that the reasonable thermodynamic parameters of the Ce–La–Fe and Ce-Nd-Fe systems were obtained finally, which would be fundamental to developing a thermodynamic database of the multi-component Nd-RE-Fe-B alloy systems and then to designing novel Nd-Fe-B permanent magnets with light rare-earth metals La and Ce. [ABSTRACT FROM AUTHOR]

Studies the thermal conductivity and magnetic moment of the inverse Mott systems BaCo0.9Ni0.1S2-y and CuIr2S4. Type of conductivity behavior that these systems showed; Examination of the entropy change for CuIr2S4; Technique used to measure the electrical conductivity and the Hall effect; Effects of increased pressure on the MI transition of BaCo0.9Ni0.1S2-y.

The effect of Gd doping on the structure and magnetic properties of PrCo 3 compound was systematically studied, and a large zero-field cooling exchange bias effect at room temperature was observed. The results show that Pr 1- x Gd x Co 3 (x = 0.0–1.0) series ribbons samples retains the rhombohedral structure of PuNi 3 type. The addition of Gd element linearly reduce the lattice constant. Large coercivity strengthening and zero-field cooling exchange bias effect were stable below Curie temperature. At 10 K, the abnormal minimum saturation magnetization M S occurs at the critical point x c = 0.6, which corresponds to the maximum critical field, and the pinning effect is the strongest. At the same time, the maximum critical field is accompanied by the strongest exchange bias field, up to 14.92 kOe, showing a large unidirectional anisotropy. The coercivity H C is also improved by pinning effect, reaching a maximum of 23.17 kOe at the critical point x h = 0.5. Due to the influence of H EB , the actual coercivity H C1 was as high as 36.23 kOe. The mechanism of these phenomena was explained specifically in this paper. This work provides a novel idea for the development of permanent magnet materials and exchange bias materials. [Display omitted] • The large coercivity and exchange bias effect was found in Pr 1−x Gd x Co 3. • Melt-spun can greatly increase coercivity and stimulate the exchange bias effect. • At 10 K, Pr 0.4 Gd 0.6 Co 3 has the maximum exchange bias field of 14.92 kOe. • At 10 K, Pr 0.5 Gd 0.5 Co 3 has the maximum actual coercivity of 36.23 kOe. • Coercivity and exchange bias effect attribute to the complex exchange of crystals. [ABSTRACT FROM AUTHOR]

In this work, phase equilibria of the Sm-Co-Zr ternary system at 1073 K and 773 K were investigated using diffusion couple method and equilibrium alloy method with scanning electron microscopy with energy dispersive spectrometry (SEM-EDS), X-ray diffraction (XRD) and electron probe microanalysis (EPMA). No stable ternary intermetallic compounds in the Sm-Co-Zr ternary system were found at 1073 K and 773 K. The solubilities of Zr in intermetallic compounds SmCo 2 , SmCo 3 , Sm 2 Co 7 , Sm 5 Co 19 , SmCo 5 and Sm 2 Co 17 at 1073 K were determined to be 7.3 at.%, 18.6 at.%, 9.9 at.%, 5.1 at.%, 1.4 at.% and 4.9 at.%, respectively, while those of Zr in these intermetallic compounds at 773 K were measured to be 4.3 at.%, 17.4 at.%, 9.5 at.%, 1.9 at.%, 0.9 at.% and 5.6 at.%. Meanwhile, the solubility of Sm in Co 23 Zr 6 was measured to be 6.5 at.% and 5.1 at.% at 1073 K and 773 K, respectively, while the solubility of Sm in other intermetallic compounds is very limited (less than 2 at.%). Isothermal sections of the Sm-Co-Zr ternary system at 1073 K and 773 K were constructed. [ABSTRACT FROM AUTHOR]

The phase relations of the Sm–Fe–B ternary system at 973 K have been determined experimentally in this study by X-ray diffraction, scanning electron microscopy and energy dispersion spectroscopy techniques. This tentative isothermal section includes 15 single-phase regions, 30 two-phase regions, and 16 three-phase regions. The phases αFe 17 Sm 2 , Fe 3 Sm, Fe 2 Sm, Sm 2 B 5 , SmB 4 , SmB 6 , SmB 66 , Fe 2 B and FeB are confirmed to exist at 973 K. The existence of the only three ternary phases Sm 2 Fe 14 B, SmFeB 4 and Sm 17 (Fe 4 B 4 ) 15 is observed. [ABSTRACT FROM AUTHOR]

A series of polycrystalline Bi 1− x La x FeO 3 (0≤ x ≤1.00) solid solution were synthesized by sol–gel method. The effects of lanthanum concentration on the phase formation, phase transition and magnetic properties were studied. The XRD results displayed that there is a clear indication of structural modification and symmetry change brought about by La doping. At room temperature the crystal structure of the solid solution transforms from rhombohedral R3c ( x ≤0.15) to tetragonal P4mm (0.15< x <0.40), then to cubic P m 3 ¯ m (0.40≤ x <0.50), and finally to orthorhombic Pbnm (0.50≤ x ≤1.00). In situ high temperature X-ray powder diffraction studies reveal that phase transformations of the rhombohedral R3c and the cubic P m 3 ¯ m to the orthorhombic Pbnm occur in the temperature regions of 680–730 °C and 300–680 °C,respectively. The phase transformations of the tetragonal P4mm to the cubic P m 3 ¯ m occurs in the temperature region of 200–230 °C, whereas the phase structure of orthorhombic Pbnm keeps unchanged below 850 °C. Based on careful characterization of crystal structure and phase transition as a function of temperature, the phase diagram of the pseudo-binary BiFeO 3 –LaFeO 3 system has been constructed. The phase diagram manifests that the Bi 1− x La x FeO 3 (0≤ x ≤1.00) solid solution provides more options to tune the magnetism and multiferroism, as the crystal structures with polarity feature occur in a wide doping concentration of La ( x ≤0.30). We then selectively studied the magnetic properties of possible multiferroic phases, i.e. R3c and P4mm phases. The results revealed that both the magnetic remanence and the coercive field of Bi 1− x La x FeO 3 (0< x ≤0.30) increased with the La content. [ABSTRACT FROM AUTHOR]

Reversals of magnetization and exchange bias field were observed around 19 K in polycrystalline perovskite chromite YbCrO 3 . Both the reversals can be elucidated based on the antiferromagnetic interaction between the ferromagnetic component of Cr 3+ moments and the Yb 3+ moments. The low field magnetization exhibits a perfect linear correlation with the magnetization shift resulted from the exchange bias effect. Distinguished from other exchange bias systems, the dependence of H E at 10 K on the cooling field shows an almost undamped feature up to 85 kOe, indicating the stable exchange bias states in respective temperature region. [ABSTRACT FROM AUTHOR]

Bi 1− x Pd x FeO 3 ( x = 0, 0.005, 0.01, 0.015) nanoparticles were prepared via a sol–gel method. A single-phase rhombohedrally distorted perovskite structure of all the samples was observed from the Rietveld refined X-ray diffraction (XRD) patterns. The magnetization was increased with the increase of Pd concentration, which mainly ascribed to the increased surface-to-volume ratio and structural distortion. The oxygen vacancy concentration was increased with Pd substitution, which is responsible for the increased leakage current. Interestingly, with the increase of Pd content, the optical band gap ( E g ) of Bi 1− x Pd x FeO 3 first increased for x = 0.005 and then decreased for x = 0.01 and 0.015, respectively. In order to explain this phenomenon, a phenomenological qualitative model based on the fluctuation of Fe–O–Fe bond angle and the concentration of oxygen vacancy was proposed. [ABSTRACT FROM AUTHOR]

The solid-state phase equilibria in the Fe–Pd–Pr ternary system at 773 K were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), differential scanning calorimetry (DSC) and energy dispersion spectroscopy (EDS) techniques. It is found that the 773 K isothermal section consists of 14 single-phase regions, 26 two-phase regions, 13 three-phase regions. At 773 K, it is observed that the highest solubility of Pr in FePd and FePd 3 are 1.4 and 1.3 at.% Pr, respectively. The solid solubility of Fe in Pd 5 Pr, Pd 3 Pr, Pd 2 Pr, Pd 3 Pr 2 , Pd 4 Pr 3 , PdPr, Pd 3 Pr 7 , and that of Pd in Fe 17 Pr 2 are very little and less than 1 at.%. In this work, at 773 K, the homogeneity ranges of phases FePd and FePd 3 in the Fe–Pd binary system have been determined to be 49.6–61.1 at.% Pd for FePd and 62.54–80.55 at.% Pd for FePd 3 , respectively. A new ternary compound Pr 6 Fe 13 Pd with space group I 4/ mcm , a = 0.80900 (7) and c = 2.24401 (4) nm was discovered. [ABSTRACT FROM AUTHOR]

In this work, phase equilibria of the Sm-Co-Fe ternary system at 1073 K, 1273 K and 1473 K were measured using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and X-ray diffractometer (XRD). No ternary intermetallic compounds were observed. The continuous solid solution phases Sm 2 (Co, Fe) 17 , Sm(Co, Fe) 3 and Sm(Co, Fe) 2 were formed from the respective Sm–Co and Sm–Fe binary intermetallic compounds due to the same phase structures. The intermetallic compound SmCo 5 with a certain solubility of Fe was confirmed to be stable at 1073 K. The solubility of Fe in SmCo 5 , Sm 5 Co 19 and Sm 2 Co 7 intermetallic compounds was determined. Based on the experimental results determined in this work and reported in the literature, thermodynamic calculation of the Sm-Co-Fe ternary system was performed using the CALPHAD method in the combination with the previous assessments of three Sm–Co, Sm–Fe and Co–Fe binary systems. The liquidus projection, isothermal sections and vertical sections of this ternary system were calculated. The good agreement between the calculated results and the experimental results was achieved. [ABSTRACT FROM AUTHOR]

We report the spin-glass-like freezing and spin reorientation transition in the geometrically frustrated magnet InBaCo 4 O 7 . The glass feature has been illustrated by the long-time magnetic relaxation which can be described by stretch exponential relaxation formula, M = M 0 + M 1 exp[−( t / τ ) 1− n ]. The memory effect observed in this compound serves as another evidence of spin glass-like freezing at low temperature. The spin-glass-like dynamic behaviour is believed be associated with the geometrical frustration. [ABSTRACT FROM AUTHOR]

The phase relations in the pseudo-binary Nd 2 Fe 14 B–Pr 2 Fe 14 B system were investigated and constructed by means of X-ray powder diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). The results revealed that similar to the end-members of the Nd 2 Fe 14 B–Pr 2 Fe 14 B system form a continuous solid solutions, all intermediate (Nd 1− x Pr x ) 2 Fe 14 B samples belong to tetragonal Nd 2 Fe 14 B-type structure (space group P4 2 /mnm). The lattice parameter a almost remains the same, and the lattice parameter c and unit-cell volume V increase linearly with an increase of Pr concentration. Based on the results of DTA measurements and X-ray powder diffraction examinations, the tentative phase diagram of the Nd 2 Fe 14 B–Pr 2 Fe 14 B isopleth has been constructed. [ABSTRACT FROM AUTHOR]

The series of polycrystalline Bi 1− x La x FeO 3 (0 ⩽ x ⩽ 0.50) ceramic powders was successfully synthesized by sol–gel method in this paper. X-ray diffraction and Rietveld crystal structure refinement software (FULLPROF) were used as complementary method to study structure and hyperfine interactions of the samples. It was a clear indication of structural modification and symmetry changes brought about by La doping. The BFO is crystallized in rhombohedrally distorted perovskite structure with space group R3c for x ⩽ 0.10. With an increase of La content, within the range x = 0.10–0.20 a structural phase evolutes from rhombohedral to cubic Pm 3 ¯ m structure, and then transits to orthorhombic Pbnm structure on further increasing the La-doping to x = 0.50. The magnetization of La-doped samples is improved with the increase of La content. The coercive field (Hc) increases remarkably with an increase in La doping and x = 0.50 exhibits the highest Hc (20.2 kOe at room temperature) reported so far in any rare earth doped BFO, which will have a great potential for practical application in non-volatile memory devices. Moreover, high-field magnetization and remanence (Mr) increase with La doping content due to the gradual change in spin cycloid structure. [ABSTRACT FROM AUTHOR]

In the present work, sixteen Mn–In alloys were investigated experimentally by means of thermal analysis and X-ray diffraction techniques. The temperatures of the invariant reactions and liquidus in the Mn–In binary system were determined. Based on the experimental results obtained in the present work and the critical review of the available experimental data from the published literature, the Mn–In binary system was assessed thermodynamically using the CALPHAD method. The solution phases including liquid, α-Mn, β-Mn, γ-Mn, δ-Mn and tetragonal_A6(In), are modeled by the substitutional solution model and their excess Gibbs energies are expressed with the Redlich–Kister polynomial. The intermetallic compound, InMn 3 , is treated as a stoichiometric compound. A set of self-consistent thermodynamic parameters obtained finally to describe the Gibbs energies of various phases in the Mn–In binary system can be used to reproduce well the phase equilibria and thermodynamic data. [ABSTRACT FROM AUTHOR]

• The effect of Cu substitution of Co on the crystal structure of the ErCo 2- x Cu x compounds has been studied in detail. • The substitution of Co by Cu changes the nature of the magnetic phase transition in the ErCo 2- x Cu x compounds. • All of the ErCo 2- x Cu x compounds show excellent magnetocaloric effects. In this paper, the crystal structure, magnetic phase transition and magnetocaloric properties of the ErCo 2- x Cu x (x = 0.12, 0.24, 0.36 and 0.48) compounds have been investigated in detail. All of the compounds crystallize in the C15 cubic Laves structure (MgCu 2 -type) with the Fd-3 m space group. The substitution of Cu for Co is accompanied by an increase of the Curie temperature T c from 31.5 K to 68 K for x varying from 0.12 to 0.48. The nature of the magnetic phase transition, determined by the results of the Arrott plots and Landau theory, changed from a first order to a second order in the ErCo 2- x Cu x compounds with the Cu content increasing. The isothermal entropy change -∆ S M is calculated according to isothermal magnetization measurements using Maxwell's relation. For an applied magnetic field change of 0–5 T, the -∆ S M decreased from 30 J kg−1 K−1 for x = 0.12 to 10.9 J kg−1 K−1 for x = 0.48, whereas the working temperature range became wider due to that the magnetic transition type changed from a first order to a second order, which is a benefit for the application of the magnetic refrigeration. The corresponding refrigerant capacity RC values are 270.8 J kg−1, 194.1 J kg−1, 261.8 J kg−1 and 264.8 J kg−1, respectively. [ABSTRACT FROM AUTHOR]

The crystal structure, microstructure, hydrogen storage properties and thermal stability of the as-cast and annealed V 35 Ti 20 Cr 45 alloys prepared by arc-melting were studied in this work. It was confirmed that the as-cast alloy is a body-centered cubic (bcc) single phase, while it consists of bcc main phase and C14-typed Laves secondary phase after annealed at 973 K for 72 h. As a result of the microstructure change, the activation performance and kinetic properties of the annealed alloy are improved greatly due to the catalysis of C14-typed Laves secondary phase in the annealed alloy. The kinetic mechanism of hydrogen absorption/desorption processes in the as-cast and annealed alloys was discussed using the Johnson-Mehl-Avrami (JMA) equation. Based on the plateau pressure data from pressure-composition-temperature (PCT) measurements with the Van't Hoff equation, the calculated formation enthalpies of the hydride formed in the as-cast and annealed alloys indicate that heat treatment results in lower thermal stability of the hydride in the as-cast alloy. Furthermore, using the Kissinger method with the peak temperatures from differential scanning calorimeter (DSC) measurements at different heating rates, the calculated activation energies of the dehydrogenation in the as-cast and annealed alloys suggest that heat treatment is very beneficial to improve hydrogen absorption/desorption capacities in the alloy. [ABSTRACT FROM AUTHOR]

Highlights: [•] It is well known that the operating temperature has a notable effect on the overall electrochemical properties. [•] The electrochemical properties of the Ni–MH batteries at low and high temperatures are poor. [•] It is necessary to improve the wide temperature range properties of hydrogen storage alloys as negative electrodes. [ABSTRACT FROM AUTHOR]

Abstract: High-field magnetization measurements of spin-chain compounds Ca3Co2−x Mn x O6 reveal the presence of two metamagnetic transitions within the Mn composition range of x=1.0–0.8. These transitions are associated with spin-configuration changes from zero-field ↑↑↓↓ to ↑↑↓↑, and finally to ↑↑↑↑ along the Cotrig–(Co/Mn)oct–Cotrig–(Co/Mn)oct spin chain. For x=0.6–0.3, however, the magnetization curve presents a single metamagnetic transition, which can be understood as a ↑↓↑↑ to ↑↑↑↑ transition. The zero-field ↑↓↑↑ structure is further supported by the results of total energy calculation of x=0.5. [Copyright &y& Elsevier]

The structure, magnetic transition and magnetocaloric effect of the intermetallic compounds (Ho 2- x Y x)Fe 17 (x = 0, 0.5, 1 and 1.5) were investigated. The compounds crystallize into a Th 2 Ni 17 -type structure with the P 6 3 /mmc space group, as determined by Rietveld refinement of the XRD powder diffraction patterns. All the samples undergo a second-order magnetic transition from the ferromagnetic to paramagnetic state, and the Curie temperature decreases from 334 K (x = 0) to 314 K (x = 1.5) with increasing Y content. In the paramagnetic region, the reciprocal magnetic susceptibilities χ−1 for (Ho 2- x Y x)Fe 17 (x = 0.5, 1 and 1.5) obey the Curie-Weiss law. The effective magnetic moment was determined to be 28.97 μ B / f.u. , 32.88 μ B / f.u. and 33.78 μ B / f.u. , respectively, with corresponding paramagnetic Curie temperatures of 323 K, 308 K and 304 K. The maximum magnetic entropy changes for (Ho 2- x Y x)Fe 17 (x = 0, 0.5, 1 and 1.5) are 3.0 J/kg K, 3.5 J/kg K, 3.8 J/kg K and 4.6 J/kg K, with corresponding refrigerant capacity values of 168 J/kg, 197 J/kg, 263 J/kg and 342 J/kg for a field change of 0–5 T. The tunable Curie temperature and considerable magnetocaloric effect indicate that (Ho 2- x Y x)Fe 17 (x = 0, 0.5, 1 and 1.5) compounds are candidates for room-temperature magnetic refrigerants. • The effective and saturation magnetic moments in the (Ho 2- x Y x)Fe 17 compounds have been studied in detail. • The Y substitution of Ho enhance the MCE in the (Ho 2- x Y x)Fe 17 compounds. • The (Ho 2- x Y x)Fe 17 compounds are potential materials for room refrigeration. [ABSTRACT FROM AUTHOR]

Abstract: Crystal structure and magnetic properties of the Nd1−x Gd x Co9.5V2.5 compounds (x=0–1) have been investigated. The compounds crystallize in the tetragonal ThMn12 structure with space group I4/mmm. The lattice parameters a, c and the unit cell volume V decrease with the increase of Gd content. The Curie temperature of Nd1−x Gd x Co9.5V2.5 increases monotonically upon the substitution of Gd for Nd. The critical field required to induce the magnetization jump decreases with increasing Gd content. The metamagnetic transition phenomenon becomes less obvious and even disappears with the substitution of Gd for Nd. The required for the metamagnetic transition increased with increasing Gd content at low substitution content. The saturation moment M S of the compounds decreases first then increases with the increased Gd content. [Copyright &y& Elsevier]

Abstract: The 1/3 magnetization step is an important feature in spin frustrated Ca3Co2O6 and can be modified by chemical doping. Taking Ca3Co2−x Mn x O6 as an example, we find that as Mn-doping reaches x=0.33–0.35, the field-induced 1/3 magnetization step, which is a manifestation of the partially disordered antiferromagnetic state, tends to vanish. The critical value of x=0.33–0.35 is consistent with the composition where the paramagnetic Curie temperature changes its sign from positive to negative, showing a correlation between the 1/3 magnetization step and the magnetic exchange interaction. [Copyright &y& Elsevier]

Abstract: The crystal and magnetic structures of the composite compound Nd2Co6Fe have been investigated by high-resolution neutron powder diffraction and X-ray powder diffraction. The compound crystallizes in the hexagonal Ce2Ni7-type structure consisting of Nd(Co,Fe)2 and Nd(Co,Fe)5 structural blocks alternately stacked along the c-axis. Multi-pattern Rietveld refinement of neutron diffraction and X-ray diffraction data at room temperature reveal that substitution of Fe for Co occurs exclusively in the Nd(Co,Fe)5 structural blocks. The preferential occupation of the Fe atoms in the structure is discussed based on the mixing enthalpy between Nd and Fe atoms and on the lattice distortions. In agreement with the reported magnetic phase diagram of the Nd2Co7−x Fe x compounds, magnetic structure models with the moments of all atoms in the ab plane at 300K and along the c-axis at 450K provide a satisfactory fitting to the experimental neutron diffraction data. The refinement results show that the atomic moments of (Co,Fe) atoms within the Nd(Co,Fe)5 blocks decrease slightly with temperature, whereas the atomic moments of Nd in the compound and of (Co,Fe) atoms at the interface between the Nd(Co,Fe)2 and Nd(Co,Fe)5 blocks are reduced significantly. [Copyright &y& Elsevier]

Abstract: The relaxation behaviors of Ce65Al10Cu20Co5 and Zr46.75Ti8.25Cu7.5Ni10Be27.5 (Vit4) bulk glass-forming supercooled liquids were investigated by frequency-dependent heat capacity measurements on a temperature-modulated differential scanning calorimetry (TMDSC) apparatus. The relaxation behaviors of the investigated samples were well described by Kohlrausch–Williams–Watts (KWW) function. The temperature dependences of characteristic relaxation time of the glass-forming liquids were fitted by Vogel–Fulcher–Tamman (VFT) equation. The derived fragility index m shows that Ce65Al10Cu20Co5 (m =31) liquid is a stronger liquid than Vit4 (m =42). The sizes of cooperatively rearranging region (CRR) for Ce65Al10Cu20Co5 and Vit4 liquids were estimated to be 1.6 and 1.4nm, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Double perovskite compounds (Sr2−x Eu x )FeMoO6 (0≤x≤0.3) were prepared by solid-state reaction at high temperature. Crystal structure, magnetic and transport properties of the compounds were investigated. The crystal structure of the compounds changes from an I4/m lattice to an Fm3¯m lattice around x=0.1. The unit-cell volume decreases with the doping level in both the I4/m lattice and the Fm3¯m lattice. The resistivity of the compounds shows a metal–semiconductor transition, and the transition temperature T M–S increases with the doping level. However, Curie temperature (T C) of the compounds exhibits a weak dependence on the doping level. The saturation magnetization (M S) at 100K varies almost linearly with the anti-site defect concentration and agrees well with the simple FIM model. In contrast to the Ce-, Pr-, Nd- and Sm-doped Sr2FeMoO6, the difference of M S of (Sr2−x Eu x )FeMoO6 between 5 and 100K indicates that the moment of Eu3+ is antiparellel to that of Fe3+ at low temperature. [ABSTRACT FROM AUTHOR]

Abstract: Crystal structure of the compounds Co40V60−2x La x has been investigated by means of X-ray powder diffraction (XRD). The compounds crystallize in the tetragonal σ phase structure with the space group P42/mnm and form a solid solution with a solubility limit of x =9.52. The lattice parameters a, c and the unit cell volume V of the compounds decrease linearly with the La content. A structure model with a preferential substitution of La for V atoms on the 8j sites accompanied by the presence of vacancies on these sites is proposed for Co40V44La8. The proposal structure model gives a satisfactory fitting to the XRD data and a reasonable La content close to the nominal composition as well as a coincidence of the calculated density with the experimentally measured one. The preferential occupation of La atoms on the 8j site is discussed based on a consideration of geometric constrain and thermodynamics. [Copyright &y& Elsevier]

Abstract: As a systematic search for suitable flux to grow zinc oxide single crystals, the subsolidus phase relations of the ternary system ZnO–Li2O–P2O5 were investigated by means of X-ray diffraction (XRD). There are 6 binary compounds, 5 ternary compounds and 17 three-phase regions in this system. A new compound, Li6Zn(P2O7)2, is found in this system based on XRD experiments. The phase diagrams of the pseudo-binary systems Li3PO4–ZnO and LiZnPO4–ZnO are investigated. It shows that the compounds, Li3PO4 and LiZnPO4, are not suitable as flux for the growth of ZnO single crystals below 1250°C. [Copyright &y& Elsevier]

Abstract: The phase composition of arc-melted alloys in the ternary system Ce–Al–Cu (Cu-poor portion) in the as-cast state were investigated by X-ray powder diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscopy (SEM) techniques. The investigated composition region consists of 16 single-phase, 32 two-phase and 17 three-phase regions. In as-cast state, the solubilities of the solid solution phases were determined. The CeAlCu compound decomposes into three phases: Ce(Al0.92Cu0.08)2, Ce(Al0.4Cu0.6)5 and Ce2AlCu2 in as-cast state. Based on the constructed phase composition regions of the investigated alloys in the as-cast state, it reveals that the reported composition region of the bulk glass alloys in the Ce–Al–Cu system falls in the three-phase regions 15–17 with α-Ce3Al as the common phase which is supposed to play an important role in the glass-forming process. [Copyright &y& Elsevier]

Abstract: Two series of (In1− x Fe x )2O3 were prepared by a solution combustion method using different fuel-to-oxidizer (i.e. glycine/metal nitrate, G/N) ratios. The crystal structure and magnetic properties of the compounds were investigated by means of X-ray diffraction, transmission electron microscopy and magnetic measurements. Detailed structural analysis shows the solubility limits of Fe in In2O3 are x=0.08 and 0.45 for the G/N ratios of 5/4 and 5/6, respectively. Crystallite size of the samples prepared with the G/N ratio of 5/6 is much smaller than that of the samples prepared with the G/N ratio of 5/4. At room temperature, the sample with x=0.01 prepared with the G/N ratio of 5/4 is paramagnetic and those with x=0.03–0.07 are ferromagnetic, whereas the samples with x=0.15–0.45 prepared with the G/N ratio of 5/6 show superparamagnetic behavior and those samples with x<0.15 are paramagnetic. Different magnetic behavior of these two series of samples could be attributed to different origins of magnetism. The magnetism of the samples prepared with the G/N ratio of 5/4 might originate from the existence of mixed valence Fe ions whereas the magnetism of the samples prepared with the G/N ratio of 5/6 could be due to the small crystallite size. [Copyright &y& Elsevier]

Abstract: Polycrystalline GdGa compound was prepared by arc-melting method. X-ray powder diffraction reveals that GdGa crystallizes in the CrB-type structure. The Curie temperature of the compound is 183K. A distinct peak associated with spin reorientation transition was shown around 100K on the magnetization versus temperature curve measured in a field of 0.05T. Isothermal magnetic entropy change (|ΔS M|) was estimated based on the magnetization isotherms. The maximum value of |ΔS M| is 4.81Jkg−1 K−1 under the applied field changing from 0T to 5.0T. The relative cooling power (RCP(S)) of GdGa compound is about 576Jkg−1 under an applied field change of 5T. The specific heat of the compound has been estimated within the framework of Debye and mean field approximations to evaluate the adiabatic temperature change (ΔT ad). [Copyright &y& Elsevier]

Abstract: Spin-dependent varistor-like electrical transport was observed in Sr-doped Nd2/3Sr1/3MnO3−δ perovskites for δ >0.05, in which magnetic grain or phase boundaries is likely to be responsible. In addition to the varistor-like phenomena below a characteristic temperature, we also present evidence for electrical-field-induced magnetic order–order precursor transition at even lower temperature in regions close to highly insulating boundaries where larger electrical fields can be placed. This electrical-field-induced metamagnetic transition was understood by the competition among double exchange, superexchange interactions and external electrical or magnetic field. [Copyright &y& Elsevier]

Abstract: In order to experimentally check the recent theoretical prediction regarding the Mn- or Fe-doped cubic ZrO2 as potential spintronic materials and to search for high-temperature ferromagnetic spintronic material, a series of Zr1− x Mn x O2 (x=0.15–0.35) and Zr1− x Fe x O2 (x=0.15–0.40) nanoparticles were prepared by a coprecipitation method. The crystal structure and magnetic properties of the compounds were investigated by means of X-ray diffraction, transmission electron microscopy (TEM) and magnetic measurements. Detailed structural analysis confirmed that single phase of Mn- and Fe-stabilized cubic zirconia was obtained. The solubility limit of Mn (or Fe) in ZrO2 is about x=0.27 (or 0.36). Magnetic measurements showed that all the samples were paramagnetic at room temperature and 5K. Existence of antiferromagnetic interactions in the samples was inferred from the fitting of magnetization data to the Curie–Weiss law. The absence of ferromagnetism could plausibly be attributed to an excess of oxygen vacancies in the Mn- or Fe-stabilized cubic zirconia. [Copyright &y& Elsevier]

Abstract: Phase diagram of the pseudo-binary system Bi2O3–Cr2O3 has been reconstructed based upon X-ray diffraction measurement and differential thermal analysis. Four intermediate phases have been determined in this system: Bi14CrO24-based solid solution (β1, space group I4/m), Bi10Cr2O21-based high-temperature solid solution (β2, orthorhombic symmetry), a new compound Bi2CrO6 (X, monoclinic symmetry) and the stoichiometric compound Bi6Cr2O15 (η phase, orthorhombic symmetry, space group Ccc2). [Copyright &y& Elsevier]

Abstract: The subsolidus phase relations of the ternary system ZnO–Na2O–P2O5 were investigated by means of X-ray diffraction (XRD). There are 7 binary compounds, 4 ternary compounds and 16 three-phase regions in this system. The phase diagrams of the pseudo-binary systems of Na2Zn5(PO4)4–ZnO and NaPO3–ZnO were also investigated by means of XRD and differential thermal analysis (DTA) methods. Na2Zn5(PO4)4–ZnO is an eutectic system with eutectic temperature about 872°C. Only narrow composition range in the Na2Zn5(PO4)4–ZnO system is suitable as flux to grow ZnO crystals. Two compounds, Na2ZnP2O7 and NaZnPO4, exist in the NaPO3–ZnO system. Two eutectic reactions, Liquid-NaPO3 +Na2ZnP2O7 and Liquid-Na2ZnP2O7 +NaZnPO4, occur existing at about 590°C and 777°C, respectively. The NaZnPO4 is formed by the peritectic reaction between liquid and ZnO at about 1007°C. In the NaPO3–ZnO system, narrow composition range can be used as flux for ZnO crystals growth below 1250°C. [Copyright &y& Elsevier]

Abstract: Strontium doped perovskite-type manganite Nd0.7Sr0.3MnO3 is synthesized by high-energy ball milling. Nd0.7Sr0.3MnO3 single phase with perovskite structure is formed completely after milling 4h and the perovskite phase decreases gradually and changes into amorphous state with increasing ball milling time up to 12h. The interesting point in this work is that the Nd0.7Sr0.3MnO3 perovskite can be formed again from the amorphous with subsequent 6h ball milling. In addition, the re-obtained perovskite seems to be more stable than Nd0.7Sr0.3MnO3 compound prepared using solid-state reaction method. [Copyright &y& Elsevier]

Abstract: Antiferromagnetic Co3O4 nanoparticles with diameter around 30nm have been synthesized by a solution-based method. The phase identification by the wide-angle X-ray powder diffraction indicates that the Co3O4 nanoparticle has a cubic spinel structure with a lattice constant of 0.80843(2)nm. The image of field emission scanning electron microscope shows that the nanoparticles are assembled together to form nanorods. The magnetic properties of Co3O4 fine particles have been measured by a superconducting quantum interference device magnetometer. A deviation of the Néel temperature from the bulk is observed, which can be well described by the theory of finite-size scaling. An enhanced coercivity as well as a loop shift are observed in the field-cooled hysteresis loop. The exchange bias field decreases with increasing temperature and diminishes at the Néel temperature. The training effect and the opening of the loop reveal the existence of the spin-glass-like surface spins. [Copyright &y& Elsevier]

Abstract: Phase relations of BiFeO3–LaFeO3 system at room temperature were investigated by X-ray powder diffraction. A rhombohedral (R3c) phase exists in the composition range of 0≤ x ≤0.1 and an orthorhombic (Pbnm) phase in the range of 0.6< x ≤1.0. Thermal expansion of single-phase samples with x =0, 0.1, 0.7, 0.9 and 1.0 was studied by temperature-dependent X-ray diffraction. The temperature dependences of expansion coefficients of the samples were obtained. Specific heat capacity of the samples with x =0, 0.1, 0.8 and 1.0 was measured in the temperature range of 200–760K by a modulated-temperature differential scanning calorimeter. The phase boundaries of the antiferromagnetic–paramagnetic transition were determined. [Copyright &y& Elsevier]

Abstract: A thermodynamic assessment of the Cu–Ga system was carried out by the CALPHAD approach (CALculation of PHase Diagram). The liquid phase, the solid solution phases of fcc (-Cu), bcc () and hcp (), the solution compounds of Cu9Ga4_0 (), Cu9Ga4_1 (), Cu9Ga4_2 () and Cu9Ga4_3 (), the stoichiometric compounds of Cu0.778Ga0.222 () and CuGa2, and the terminal phase of orthorhombic-Ga were taken into consideration in the optimization. The substitutional solution model was used for the liquid phase and the solid solution phases of fcc, bcc and hcp. The solution compounds related to Cu9Ga4 were described with the sublattice model. The order–disorder transformation between Cu9Ga4_0 () and Cu9Ga4_1 () was considered. In the model description of Cu9Ga4_2 () and Cu9Ga4_3 (), vacancies were considered. Differential scanning calorimetric analysis was conducted to obtain phase transformation temperatures and the enthalpies of fusion of Cu–Ga alloys. A set of self-consistent thermodynamic parameters were obtained and the calculated phase diagram and thermodynamic properties were presented and compared with experimental data. [Copyright &y& Elsevier]

Abstract: Subsolidus phase relations in the ternary system SnO2–TiO2–Y2O3 have been investigated by means of X-ray powder diffraction. The samples are prepared by solid-state chemical reaction method at 1400°C. The solid solution miscibility gap at room temperature for the TiO2–SnO2 system was determined to be content 22–68mol% SnO2, based on accurate determination of lattice parameters as functions of composition. The Y2Ti2−x Sn x O7 forms a complete solid solution with pyrochlore-type structure. [Copyright &y& Elsevier]

Abstract: We present a systematic investigation on the structural and magnetic properties of Zn1− x Co x O nanoparticles synthesized by an auto-combustion method. The single-phase Zn1− x Co x O crystallize in the wurtzite-type structure with a homogeneity range as large as x≈0.30, which enables the observation of some anomalies. The lattice parameter a and the unit cell volume V increase with the Co content, and anomalies are discernable around x=0.15 on the a−x and V−x curves. The magnetization data show no evidence of ferromagnetic (FM) ordering in our samples down to T=5K, and the magnetization at 5K and 5T exhibits a maximum around x=0.125. Based on the detailed analysis of the magnetization data and the donor impurity band exchange model, the anomalies on composition dependence of both the lattice parameters and magnetization can be associated with an occurrence of cation percolation around the threshold x p (≈1.5/Z=0.125 for three-dimensional lattice with coordination number Z=12). Within the framework of the donor impurity band exchange model, the absence of FM in the well-characterized Zn1− x Co x O can be attributed to insufficient donor electron concentration. [Copyright &y& Elsevier]

Abstract: Polycrystalline samples of Gd(Co1−x Mn x )2 have been prepared by arc-melting method. The compounds form a complete solid solution with the MgCu2-type structure and the lattice constant varies monotonically as a function of the Mn content with a negative deviation from the Vegard’s law. The Curie temperatures of the compounds have been determined by thermomagnetic measurements and the thermogravimetric analysis. Isothermal magnetic entropy change of the samples with , 0.7, 0.8, and 0.9 have been calculated by the magnetization isotherms. In the four samples, the addition of Mn decreases the Curie temperature, while the increases. [Copyright &y& Elsevier]

A new compound, Na2Zn5(PO4)4, was identified in the system ZnONa2OP2O5 and high-quality crystal was obtained by the melt method. The crystal structure of this compound was solved by direct method from single crystal X-ray diffraction data. The structure was then refined anisotropically using a full-matrix least square refinement on F2 and the refinement converged to R1=0.0233 and wR2=0.0544. This compound crystallizes in the orthorhombic system with space group Pbcn, lattice parameters a=10.381(2) Å, b=8.507(1) Å, c=16.568(3) Å and Z=4. The structure is made up of 3D [Zn5P4O16]n2n− covalent framework consisting of [Zn4P4O16]n4n− layers. The powder diffraction pattern of Na9Zn21(PO4)17 is explained by simulating a theoretical pattern with NaZnPO4 and Na2Zn5(PO4)4 in the molar ratio of 1:4 and then by Rietveld refinement of experimental pattern. Na2Zn5(PO4)4 melts congruently at 855 °C and its conductivity is 5.63×10−9 S/cm. [Copyright &y& Elsevier]

Abstract: A series of RFe11Mo compounds (R=Y, Nd, Gd, Tb, Dy, Ho and Er) with the ThMn12-type structure have been synthesized. The structural and magnetic properties of the compounds have been investigated by means of X-ray diffraction (XRD) and magnetic measurements. The lattice parameters a, c and the unit-cell volume V of the compounds decrease with decreasing the atomic radius of the rare earth element due to the lanthanide contraction. The spin-reorientation transition (SRT) was investigated in detail. For HoFe11Mo, no SRT was observed. For NdFe11Mo, TbFe11Mo and ErFe11Mo one SRT was observed, while for DyFe11Mo two SRTs were observed. By minimizing the magnetocrystalline anisotropy energy, theoretical SR temperatures of the compounds are derived, which show a reasonable agreement with the experimental values. [Copyright &y& Elsevier]

Abstract: The phase diagram of the Ag–Ga binary system and the phase relations of the Ag–Ga–N system are studied by DTA and X-ray powder diffraction. The equilibrium phase diagram of the Ag–Ga system is reconstructed. Two intermetallic phases are determined in the Ag–Ga system: the Ag2Ga compound and a novel δ-Ag3Ga2 with the composition about 40at.% Ga. The novel phase δ-Ag3Ga2 which is the product of the peritectic reaction Ag2Ga+L↔δ-Ag3Ga2 at 575K is indexed with an orthorhomic lattice with lattice parameters a =6.7276(2)Å, b =3.8840(1)Å, c =3.2200(1)Å and V =84.14Å3. The temperature-dependent lattice parameters of ζ′-Ag2Ga with 28at.% Ga are measured by temperature-dependent X-ray powder diffraction from 93 to 543K. The linear temperature dependences of the expansion coefficients along the direction of a- and c-axis and volume coefficients are obtained, α a =(1.4741+0.0028T)×10−5, α c =(1.1710+9.1349×10−4 T)×10−5 and α V =(4.1167+0.0065T)×10−5, respectively. No ternary phase is found in the Ag–Ga–N system and no solubility of Ag in GaN is observed under the present experimental conditions. [Copyright &y& Elsevier]

Abstract: A solid solution with formula (Y1−x Tb x )3GaO6 (x =0–0.5) was prepared by solid-state reaction method. Powder X-ray diffraction (XRD) shows that Y3GaO6 is isostructural to Gd3GaO6 (Cmc21), and the lattice parameters are a =8.8364(1)Å, b =11.0899(1)Å and c =5.3937(1)Å. Atomic parameters were derived by Rietveld refinement of the XRD pattern. Photoluminescence (PL) spectra show a strong green emission of 543nm from the 5D4 → 7F5 transition of Tb3+ at room and liquid nitrogen temperature. There is a wide saturation range of the PL intensity for the Tb3+ content from x =0.04–0.20, and a long life time about 1200μs for the green 543nm emission at room temperature. [Copyright &y& Elsevier]

Abstract: The thermodynamics of the Ag–Ga system are assessed by the CALPHAD approach (calculation of phase diagram). The liquid phase, the solid solution phases of fcc (-Ag) and hcp , the solution compound Ag2Ga , the stoichiometric compound Ag3Ga2, and the terminal phase of orthorhombic Ga are taken into consideration in this optimization. The liquid phase is described by the association model. The subregular solution model is used for the solid solution phases of fcc and hcp. The solution compound Ag2Ga is described by the two-sublattice compound energy model (CEM). A set of self-consistent thermodynamic parameters is obtained and the calculated phase diagram and thermodynamic properties are presented and compared with the experimental data from literatures. [Copyright &y& Elsevier]

Abstract: The crystal and magnetic structures of the Laves phase compound NdCo2 in the temperature range from 9 to 300K are determined by Rietveld refinement technique, using high-resolution neutron powder diffraction data. The compound crystallizes in space group above the magnetic ordering temperature T C (≈100K), in space group I41/amd below T C and in space group Imma below the tetragonal–orthorhombic structural/magnetic transitions at T M ≈42K. The assignment of the space groups to the crystal structures of NdCo2 in different temperature ranges complies with the reported Mössbauer studies. Detailed information of the crystal and magnetic structures of NdCo2 at different temperatures are reported. [Copyright &y& Elsevier]

Abstract: Two serials of Eu3+ doped AlN films are prepared by means of magnetron RF reactive sputtering under different RF powers and N2/(N2 +Ar) ratios. XRD analysis indicates that the films change from amorphous to c-axis oriented crystalline as the RF power increases or as the N2/(N2 +Ar) ratio decreases. Lower N2/(N2 +Ar) ratio and higher RF power enhance the deposition rate and crystallinity. The grain size and surface roughness observed by SEM and AFM increase with the increase of the RF power. The emission from 5D0 to 7F J (J =0–4) of Eu3+ is observed in the PL spectra for all the crystalline films, and the 5D0 to 7F2 transition of the films grown at 300W has double exponential decays, 38 and 161μs. The crystalline quality of the films improves the photoluminescence intensity. [Copyright &y& Elsevier]

Abstract: Nanometer titanium dioxide (TiO2) films were deposited on muscovite flakes and doped with a number of different metal ions (Al3+, Sn4+, Fe3+, Cu2+, Co2+, Mn2+ or Zn2+) using a chemical liquid deposition method. The morphology and the anatase–rutile (A–R) transformation were studied by scanning electronic microscopy (SEM) and X-ray diffraction (XRD), respectively. Apart from round particles, SEM micrographs show that euhedral pillar rutile grains are found in the samples doped with Fe3+, Mn2+ or Zn2+ ions. The rutile phase of TiO2 thin layers on muscovite could be generated at low temperature, 60 °C. The XRD results confirm that the addition of metal ions affects the anatase–rutile (A–R) transformation. The Mn2+, Sn4+, Fe3+ and Zn2+ ions promote the A–R transformation while the Al3+, Cu2+ and Co2+ ions inhibit the A–R transformation of TiO2 thin layers on muscovite. The influence of metal ion doping on the A–R transformation of the TiO2 thin layers on muscovite depends on the substitution of foreign ions for Ti4+ ions in TiO2 thin layers. [Copyright &y& Elsevier]

Abstract: The crystal structures of the ζ-phase and ζ′-phase have been determined by X-ray powder diffraction and refined by Rietveld method. The space group of the ζ′-phase is with the lattice parameters a =7.7710(1) and c =2.8788(1)Å. The ideal formula is Ag2Ga (real composition Ag2+x Ga1−x , x =0.16) and the chemical formula per unit cell is Z =3. Six Ag atoms occupy the 3g positions with x =0.63970(8) and the 3f positions with x =0.30347(9), respectively. Three Ga atoms occupy the 2c and the 1b sites. The ζ-phase is obtained by quenching the sample containing 20at.% Ga from 500°C to room temperature. Its space group is close-packed hexagonal, P63/mmc, and the lattice parameters are a =2.8818(1) and c =4.6956(1)Å. There are 2 atoms (1.5Ag+0.5Ga) per unit cell, which occupy the 2c site statistically. The relation between the structures of the ζ- and ζ′-phase is discussed. [Copyright &y& Elsevier]

Abstract: The crystal structure and magnetic properties of Sm(Co,M)7 (M=Si, Cu, Ti, Zr, and Hf) compounds with the TbCu7-type structure have been investigated by means of X-ray powder diffraction and magnetic measurements. For the Sm(Co,M)7 compounds, the formation of the compound is dominated by the enthalpy of formation of MCo7, atomic radius ratio of Sm to (Co, M) and the electronic configuration of the doping element M, while the site occupation of M is determined by the enthalpies of solution of M in liquid Sm and Co as well as by the electronegativity difference among M, Sm and Co. However, the Sm(Co,Cu)7 compounds exhibit different stabilizing mechanism, which may be due to the large mutual solubility between Co and Cu in the Sm(Co,Cu)7. The stabilizing element Si and Cu prefer to occupy the 3g site, whereas Ti, Zr and Hf have preference to occupy the 2e site. Both the saturation magnetization and Curie temperature of the Sm(Co,M)7 compounds decrease with increasing M content, while the magnetic anisotropy increases with increasing M content. The magnetic anisotropy field is related closely to the content and site occupation of the doping element M, which agrees with the theoretical analysis based on the individual site contribution model. [Copyright &y& Elsevier]