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A series of nanocrystalline La 1- x Bi x FeO 3 (0.0≤ x ≤ 0.5) ceramic powders were successfully prepared by the sol-gel method. X-ray diffraction and transmission electron microscopy were used to investigate the crystal structure evolution and hyperfine interactions of the samples. The average diameter of the powders was revealed to be approximately 80 nm. All the samples were crystallized into an orthorhombic crystal structure (space group Pnma) with no second phase. The magnetization of the Bi-doped samples obviously improved with increasing Bi content. A remarkable antiferromagnetic/ferromagnetic transition was detected at x ≥ 0.2, and a high coercive field of 23.05 kÖe was obtained with x = 0.5. The high correlation between the magnetization parameters and bonding characteristics indicated that significant stretching of the Fe3+-O d 2- bonds and a decrease in Fe3+-O d 2--Fe3+ linkage angles were the main origins of the strong ferromagnetism in the Bi-doped systems. [ABSTRACT FROM AUTHOR]

The crystal structure, magnetic, and microwave absorption properties of the (Nd1−xLax)2Fe14B system have been investigated. The La2Fe14B compound was successfully synthesized and refined, giving a tetragonal structure, space group P42/mnm with the Nd2Fe14B-type structure. The crystal structure parameters of the (Nd1−xLax)2Fe14B compounds were determined by full-profile Rietveld refinements. The results revealed that all intermediate alloys form a continuous solid solution. The normalized lattice parameters of the (Nd1−xLax)2Fe14B compounds increase linearly with an increase of La concentration. Based on the results of DSC measurements and X-ray powder diffraction examinations, the phase diagram of the Nd2Fe14B-La2Fe14B system has been constructed. The remanence (Mr) and coercivity (Hc) of (Nd1−xLax)2Fe14B (x = 0.00, 0.10, 0.20, 0.30, and 0.40) gradually decrease. The highest reflection loss is − 29.8, − 27.4, − 24.1, − 18.6, and − 14.2 dB at 9.8, 8.9, 7.5, 6.9, and 6.5 GHz, respectively. The absorption peak shifts toward from higher frequency region to lower frequency region and the absorption bandwidth widens with the increase of the La substitution. [ABSTRACT FROM AUTHOR]

This paper investigated the influence of Nd substitution on the microstructure, element valences, magnetic characteristics, and microwave absorption performances of Bi 1– x Nd x FeO 3 (x = 0.0, 0.05, 0.10, 0.15) nanopowders prepared via the sol-gel technique. The crystal structure of the nanopowders transformed from a twisted rhombohedral (R3c) for x ≤ 0.10 to cubic (Pm 3 ¯ m) for x = 0.15. When Nd substitution increased, the particle size gradually decreased and the surface morphology became uniform. Analysis of the results illustrate that Nd substitution can reduce the content of oxygen vacancies and effectively enhance magnetic performance. The results show that an appropriate amount of Nd doping can effectively enhance the microwave absorption performance of the Bi 1– x Nd x FeO 3 nanopowders. The sample with x = 0.10 demonstrates exceptionally good microwave absorption characteristics (RL min value of approximately −33.7 dB at 12.1 GHz and the maximum effective bandwidth of 2.8 GHz at 2.0 mm). Therefore, the Bi 1– x Nd x FeO 3 nanopowders have various potential applications due to outstanding microwave absorption performance and wide bandwidth. Image 1 • The Bi 1– x Nd x FeO 3 (x = 0.0, 0.05, 0.10, 0.15) nanopowders were readily prepared. • Nd-doping causes a transition from rhombohedral structure to cubic structure. • An decrease oxygen vacancies is observed with Nd doping. • Nd substitution can effectively improve the magnetic properties and microwave absorption properties of BiFeO 3. [ABSTRACT FROM AUTHOR]

Abstract: Phase equilibria in the Dy–Fe–Cr system were investigated by X-ray powder diffraction (XRD), differential thermal analysis (DTA), scanning electron microscopy (SEM) techniques and the isothermal section at 773K was obtained. It consists of 8 single-phase regions, 14 two-phase regions and 7 three-phase regions. The existence of the compound DyFe12−x Cr x (1.6≤ x ≤3.0, space group I4/mmm) with ThMn12-type structure was confirmed. The maximum solid solubility of Cr in Fe, Dy2Fe17, Dy6Fe23, DyFe3 and DyFe2 is about 15, 13, 6, 5 and 16at.%, respectively. [Copyright &y& Elsevier]

Abstract: The isothermal section of the phase diagram of the ternary system Y–Mg–Ni (Ni≥50%) was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analysis (DTA). The isothermal section consists of 13 single-phase regions, 25 two-phase regions and 13 three-phase regions. At 673K, the existence of two ternary compounds YMgNi4 (space group , a =7.1853nm) and YMg2Ni9 (space group , a =4.8666(5)nm, c =23.7733(5)nm) were confirmed. No other ternary compound was found and no solid solubility was observed in this work. [Copyright &y& Elsevier]

The phase relations in the Nd–Al–Ti ternary system at 500 °C were investigated by powder X-ray diffraction (XRD), differential thermal analysis (DTA), optical microscopy, and scanning electron microscopy (SEM) techniques. The existence of two ternary compounds NdTi2Al20 and Nd6Ti4Al43 were confirmed. The isothermal section of this ternary system consists of 15 single-phase regions, 29 two-phase regions, and 15 three-phase regions. At 500 °C, the maximum solid solubilities of Ti in Nd3Al, Nd2Al, and NdAl2 is about 2.4, 3.5, and 16.1 at.%, respectively, and that of Nd in Ti, Ti3Al, TiAl is less than 1 at.%. [Copyright &y& Elsevier]

Abstract: Phase equilibria were established in the Dy–Co–V ternary system at 773K by X-ray powder diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscopy (SEM). The result shows that the isothermal section consists of 13 single-phase regions, 23 two-phase regions and 12 three-phase regions. The maximum solid solubilities of V in (Co), Dy2Co17, DyCo3, DyCo2, Dy12Co7 and Dy3Co are about 6.5, 10.0, 2.0, 6.3, 1.5 and 5.0at.% V, respectively. It is found that there is some homogeneity range in the only ternary compound of DyCo12−x V x with x = 1.6–3.8 at 773K. There is no solubility of V in Dy2Co7 observed at 773k. The binary compounds Dy4Co3 and DyCo5 are not observed at 773K. [Copyright &y& Elsevier]

The thermal stability and refined crystal structure of ternary La 2 Fe 14 B compound were investigated by integrating X-ray powder diffraction, electron probe microanalyzer and differential scanning calorimetry techniques. It was found that La 2 Fe 14 B is a high-temperature stable ternary compound, which decomposes with a eutectoid reaction: La 2 Fe 14 B→La + Fe + LaFe 4 B 4 at 794 °C and melts via a peritectic reaction: Fe + Fe 2 B + Liquid→La 2 Fe 14 B at 926 °C. By investigating the effects of La substitution on the magnetic properties of Nd 2- x La x Fe 14 B alloys, it was revealed that the Nd 1.3 La 0 · 7 Fe 14 B alloy still keeps excellent maximum energy product (113 kJ/m3), intrinsic coercivity (523 kA/m) and high remanent magnetic polarization (0.83 T). Moreover, the magnetic improvement mechanisms of Nd 2- x La x Fe 14 B alloys were also discussed in detail. The present work is beneficial to design high-performance 2:14:1-type magnets with low-cost and abundant La addition. • Single-phase La 2 Fe 14 B ternary compound was successfully prepared. • The La 2 Fe 14 B (space group P 4 2 / mnm) crystallizes in a tetragonal unit cell with the lattice parameters a = 0.8835(5) nm and c = 1.2375(8) nm. • The magnetic properties of (Nd 2- x La x)Fe 14 B alloys decreases with increasing La substitution. • Excessive addition of La (x ≥ 0.9)could inhibit the formation of RE 2 Fe 14 B main phase and increase the fraction of α-Fe. [ABSTRACT FROM AUTHOR]

Abstract: The phase equilibria of the Gd–Ni–V system at 773K were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). The experimental results show no existence of ternary compounds at 773K. The existence of 14 single-phase regions, 25 two-phase regions and 12 three-phase regions was determined. The maximum solubility of V in (Ni), Gd2Ni17, GdNi5 and GdNi2 was measured to be about 16at.%, 2at.%, 3at.% and 2.5at.%, respectively, while that of Gd in (Ni), Ni3V, Ni2V, Ni2V3, NiV3 and (V) was less than 1at.%. An isothermal section of the Gd–Ni–V system at 773K has been presented according to the present work. [Copyright &y& Elsevier]

Abstract Porous Li 3 V 2 (PO 4) 3 @C/AB hollow microspheres have been synthesized in a large-scale using a combined method of spray drying and solid-state reaction. The structure and electrochemical properties of the Li 3 V 2 (PO 4) 3 @C/AB samples are characterized by various physical characterization techniques as well as electrochemical measurements. XRD results reveal pure highly crystalline Li 3 V 2 (PO 4) 3 with the monoclinic structure. SEM and TEM images show the porous hollow structure and a uniform carbon coating layer of the samples. The sample with a carbon content of 8.94 wt% exhibits remarkable rate capability and long-term cycling performance, delivering an initial discharge capacity of 109.8 mAh g−1 at 1 C within a voltage range of 3–4.3 V versus Li/Li+, and a capacity retention of 98.5% over 200 cycles. Even at 20 C, the sample presents an initial discharge capacity of 95.8 mAh g−1 and a capacity retention of 71.8% after 2000 cycles. The remarkable cycling performance can be attributed to the synergistic effect of porous hollow structure and uniform carbon coating of Li 3 V 2 (PO 4) 3 @C/AB cathode materials. This work demonstrates the porous Li 3 V 2 (PO 4) 3 @C/AB hollow microspheres are promising cathode materials for practical application in lithium-ion batteries. Graphical abstract Image 1 Highlights • Porous Li 3 V 2 (PO 4) 3 @C/AB hollow microspheres are prepared by a spray drying method. • The sample demonstrates outstanding rate and long-term cycling performances. • A discharge capacity of 98.5 mAh g−1 is obtained at 20 C. • The capacity retention is 98.5% after 200 cycles at 1 C. [ABSTRACT FROM AUTHOR]

Through arc smelting and high energy ball milling method to synthesized the powders of La x Nd 2- x Fe 17 ( x =0.0, 0.2, 0.4, 0.6). By x-ray diffraction (XRD), scanning electron microscopy (SEM) and laser particle analyzer (LPS) to study the structural, morphology, particle size distribution of the powders, respectively. The electromagnetic parameters and saturation magnetization of the powers were measured by a vector network analyzer (VNA) and vibrating sample magnetometer (VSM), respectively. The saturation magnetization decreases with the La increasing. The minimum absorption peak frequency shifts towards a lower frequency region with an increase of La concentration. The microwave absorbing properties of the composite with different ratios of La 0.2 Nd 1.8 Fe 17 /Ni were studied. The microwave absorbing peaks of the composite shift to higher frequencies, and the microwave absorbing properties improved with the Ni content increase to 20%. The minimum reflection loss is −32.5 dB at 9.8 GHz and the bandwidth less than −10 dB (Microwave absorption rate 90%) reaches 3 GHz with a thickness of 1.8 mm. [ABSTRACT FROM AUTHOR]

Perovskite LaCoO 3 has unique mixed ionic electronic and structural defects, which has high research value in microwave absorption field. LaCoO 3 precursor was prepared by sol-gel method, and LaCo 1− x Fe x O 3 (Fe-LCO, x = 0, 0.05, 0.1 and 0.15) with rhombic symmetric structure was successfully synthesized at 600 °C. By refinement of X-ray diffraction (XRD) (Rietveld analysis), it was found that Fe doping makes LaCoO 3 lattice constant and cell volume increase. As a dielectric loss microwave absorbing material, the electromagnetic attenuation of LaCoO 3 is mainly due to the conduction loss, while the interface and dipole polarization are secondary reasons. It finds that Fe doping can improve the wave absorption performance of LaCoO 3. The best absorbing performance was obtained when Fe content is x = 0.1, with the maximum reflection loss of − 38.99 dB at 10.8 GHz and the effective absorption bandwidth (RL<−10 dB) is 4.48 GHz, while the corresponding thickness was only 3 mm. In summary, LaCoO 3 has broad application prospects in X and Ku bands. • The study focus on rare earth perovskite can expand and popularized of their application in the field of absorption. • LaCo 1- x Fe x O 3 composites have tunable Impedance matching performance and high-performance microwave absorption by ions doping. • The influence of dielectric loss and magnetic loss on material is analyzed in detail. • Composites can still maintain the effective bandwidth at 4–5 GHz when the reflection loss reached − 30 dB and above. • This work develops the application potential of LaCoO 3 in the field of absorption other than photocatalytic field. [ABSTRACT FROM AUTHOR]

• La 1– x Ca x FeO 3 microwave absorbing ferrite material was quickly synthesized by a simple sol-gel method. • The amount of Ca doping was crucial in determining the magnetic properties and electromagnetic parameters of LaFeO 3. • Conduction loss is the primary reason for microwave absorption. • The effective absorbing bandwidth of La 0.85 Ca 0.15 FeO 3 reaches 4.56 GHz and covering almost the entire Ku-band. Rare-earth orthoferrites (RFeO 3) is emerging as a type of microwave absorbing material (MAM) with development potential because of its excellent structural stability and moderate permittivity and amount of potential energy present. In this study, we employed a simple sol–gel technology to quickly synthesize La 1− x Ca x FeO 3 (x = 0, 0.05, 0.1, 0.15, and 0.2) ferrite MAMs. The FullProf X-ray diffraction refinement demonstrated that all samples formed single-phase LaFeO 3 (space group: Pnma). The amount of Ca doping was crucial in determining the particle size, magnetic properties, and electromagnetic parameters of LaFeO 3. As a dielectric loss type in MAM, conduction loss is the primary reason and interfacial as well as dipolar polarizations are the secondary reasons for the attenuation of the electromagnetic energy of the samples. The study discovered that an appropriate amount of Ca2+ doping improves LaFeO 3 microwave absorption. Therefore, the ideal microwave absorption is achieved in the La 1− x Ca x FeO 3 samples when Ca content x = 0.1 and 0.15, where the minimum reflection loss (RL min) of La 0.9 Ca 0.1 FeO 3 is − 39.90 dB at 6.72 GHz and the corresponding matching thickness is 4.0 mm. Although the RL min of La 0.85 Ca 0.15 FeO 3 is − 24.37 dB at 13.44 GHz, the effective absorption bandwidth is 4.56 GHz and the corresponding matching thickness is only 2.0 mm, which almost covers the entire Ku-band. This La 1− x Ca x FeO 3 is expected to be an industrially produced high-performance MAM owing to its excellent microwave absorption performance as well as its simple and rapid synthesis method. [ABSTRACT FROM AUTHOR]

The phase relationships in the La–Ni–Sn ternary system at 673 K have been investigated by means of X-ray powder diffraction (XRD), differential thermal analysis (DTA), scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Most of this ternary system was studied at 673 K. At this temperature, a new ternary compound whose atomic ratio is close to La/Ni/Sn=1:1:3 has been found. The existences of 15 binary compounds La7Ni3, LaNi, La2Ni3, La7Ni16, LaNi3, La2Ni7, LaNi5, Ni3Sn, Ni3Sn2, Ni3Sn4, La5Sn3, La5Sn4, LaSn, La3Sn5, LaSn3 and seven other ternary compounds LaNi5Sn, LaNi4Sn2, LaNi2Sn2, La3Ni2Sn6, La3Ni2Sn7, La3Ni8Sn16, LaNiSn have been confirmed too. There are 31 three-phase regions in the 673 K isothermal section. Due to the lower melting point of Sn (about 504 K), a small part of the ternary system that lies in the Sn-rich part was studied at 483 K. [Copyright &y& Elsevier]

Abstract: The isothermal section of the phase diagram of the ternary system Y–Ni–V at 773K was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS) techniques. It consists of 16 single-phase regions, 29 two-phase regions and 14 three-phase regions. At 773K, the maximum solid solubility of V in Ni, Y2Ni17, YNi5, Y2Ni7, YNi3, and YNi2, is about 17, 1, 2, 2, 2 and 2 at.%, while Y in Ni, Ni3V, Ni2V, Ni2V3, NiV3 and V does not exceed 1 at.%. No ternary compound has been observed in this work. [Copyright &y& Elsevier]