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Herein, we report the synthesis, structure and magnetic properties of Y-substituted CoTi-SrM hexaferrite Sr1−xYxFe10CoTiO19 (0.00 ≤ x ≤ 0.20) through a series of systematical measurements. The single phase of polycrystalline SrM hexaferrites can be obtained within the concentration x ≤ 0.15, and the lattice constants (a and c) show a corresponding variety due to the difference of substituted ionic radius (Δr). Besides, FTIR spectra also give the characteristic features of Fe3+–O2+ intrinsic vibration at tetrahedral and octahedral sites, which further confirm the integrity of M-type hexagonal magnetic structure. The comprehensive magnetic measurements [M(T) and M(H)] indicate a considerable results of temperature and magnetic properties. Especially, Ms can be improved to 79.19 emu/g under the definite substitution, and the soft magnetic behavior can also be preserved because of the fairly low Hcj. On the basis of the analyses in our present work, this substituted hexaferrite exhibits a quite promising candidate for high-frequency multilayer inductors. [ABSTRACT FROM AUTHOR]

Magnetoplumbite-type (M-type) barium ferrites doped with different Y–Co doping content Ba0.95Y0.05Fe12−xCoxO19 (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5) were successfully prepared by ceramic process and investigated in this paper for the first time. X-ray diffraction were used to analyze the phase of the prepared sample. The scanning electron microscopy (SEM) was used to measure the morphology, and magnetic properties were measured by vibrating sample magnetometer (VSM). The results of XRD show that the single phase of M-type barium ferrites was obtained with the increase of Co content (x), but α-Fe2O3 occurred when x exceeds 0.3. The SEM results exhibit the uniform plane hexagonal structures of M-type ferrites with all range of Co doping content. VSM results display that magnetization (Ms) and coercivity (Hc) show the same tendency that their values first increase and then decrease with the increase of Co content. [ABSTRACT FROM AUTHOR]

The W-type hexagonal ferrites with the composition SrLaCoFeO (0 ≤ x ≤ 0.35) magnetic powders were synthesized by the solid state method. The phase constituents, micro-morphology, and magnetic properties of the particles were investigated by x-ray diffraction (XRD), a scanning electron microscope, and a vibrating sample magnetometer. The single phase was observed in the W-type ferrites with different La content from XRD. The micro-morphology of the particles exhibits the hexagonal plate-like shape, and the particles are distributed homogeneously of W-type ferrites with different La content. The coercivity ( H ) of the particles increases with the increase of La content ( x), while the saturation magnetization ( M ) of the particles first increases with x from 0 to 0.15, and then begins to decrease when x continues to increase. [ABSTRACT FROM AUTHOR]

Sn 4+ -substituted Ni 0.65 Zn 0.35 Sn x Fe 2- x O 4 ( x = 0–0.08) soft ferrites were prepared by solid-state reaction method. The structural characteristics and electromagnetic properties were investigated by X-ray diffraction (XRD), LCR Tester, B-H analyzer, respectively. It was found that lattice constant ( a ) increased gradually, saturation magnetic flux density ( B s ) continuously decreased while initial permeability ( μ i ) increased initially and then decreased with increasing of Sn 4+ content. Power loss ( P cv ) decreased when the temperature increased. However, initial permeability had an opposite change with P cv . Our results showed that the material as a power transformer core had a lower power loss over room temperature. [ABSTRACT FROM AUTHOR]

W-type ferrite BaMg 1.8 Cu 0.2 Fe 16 O 27 magnetic powders and magnets were prepared by a ceramic process. The phase identification of magnetic powders was performed by X-ray diffraction. At calcination temperatures ranging from 1200 to 1340 °C, the phase compositions of the magnetic powders consist of W-type hexaferrites together with small amount of impurity phases such as α-Fe 2 O 3 . At calcination temperatures above 1280 °C, single-phase W-type hexaferrites can be obtained. The microstructures of the magnets were investigated by field emission scanning electron microscopy. The particles appear in hexagonal plate-like shape and the particles are distributed homogeneously. The radial shrinkage of the magnets increases with the increase of calcination or sintering temperature. The magnetic properties of the magnets was measured by a permanent magnetic measure equipment. For high remanence, intrinsic coercivity, magnetic induction coercivity and maximum energy product, the optimized calcination temperatures is 1280 °C. [ABSTRACT FROM AUTHOR]

A series of W-type hexagonal ferrites with the composition Ba 1 - x Sr x Fe 2 2 + Fe 16 3 + O 27 (0≤ x ≤1) were prepared by the ceramic process in a reducing atmosphere during the whole process of pre-sintering and sintering. The phase composition, micro-morphology, and magnetic properties of the particles were investigated by XRD, SEM, and VSM. The results of XRD show that the single phase was observed in the W-type ferrites with different Sr content. The micro-morphology of the particles exhibits the uniform plane hexagonal structures of W-type ferrites with different Sr content. The coercivity ( H c ) of the particles increases with the increase of Sr content ( x ), while the saturation magnetization ( M s ) of the particles first decreases with x from 0 to 0.2, and then begins to increase when x continues to increase. [ABSTRACT FROM AUTHOR]

A series of W-type hexagonal ferrites with the composition Ba 1− x Ca x Co 2 Fe 16 O 27 ( x =0, 0.1, 0.3, 0.4 and 0.5) were synthesized using a sol–gel method. The effects of doping on structural and magnetic properties are studied by X-ray diffraction, thermal analyzer, scanning electron microscopy, vibrating sample magnetometer and vector network analyzer, respectively. The X-ray diffraction analysis shows that the samples belong to the W-type hexagonal ferrite. The lattice constants a and c decreases as Ca contents increases. The grains exhibit well defined hexagonal shape. The saturation magnetization and the intrinsic coercive force increases with the increase of the Ca substitution amount. The real part of complex permittivity ( ε ′) and imaginary part ( ε ″) increase with more addition of Ca 2+ amount. The imaginary part of complex permittivity ( μ ′) increases and the real part ( μ ′′) goes down after Ca 2+ is doped. Furthermore, the Ca 2+ ions doped in the ferrite improved microwave absorbency. [ABSTRACT FROM AUTHOR]