Abstract Strontium substituted barium hexaferrites i.e., Ba 1 - x Sr x Fe 11 Cr 1 O 19 with x = 0.0–0.8 were prepared via co-precipitation technique. Single-phase magnetoplumbite structure was confirmed for all samples by X-ray diffraction, whereas scanning electron microscopy showed the variation in microstructure on Sr2+ substitution. Magnetic measurements revealed that the substitution causes prominent enhancement in saturation magnetization and coercive field for x = 0.4 sample. However, under same condition, decrease in real part of dielectric permittivity, dielectric loss tangent and ac conductivity were observed by impedance spectroscopy, while these parameters started to increase for x > 0.4. The dielectric permittivity exhibited frequency-dependent dispersive behavior due to Maxwell-Wagner interfacial polarization whereas weak ferroelectric hysteresis loops were obtained for the prepared samples. Moreover, it was found that the Sr2+ substitution substantially enhanced the resistive properties which is elucidated in term of localization of charge carrier’s mobility due to reduction in Fe 3 + - O - Fe 2 + network and microstructural variations. Here, it is proposed that x = 0.4 sample exhibits maximum magnetization (64 emu/g), moderate real part of dielectric permittivity at low frequency (>103), diminished dielectric loss tangent (~0.05) and colossal value of resistance (~1010 Ω) which makes this material interesting for high frequency applications.

中文翻译：

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锶取代对 Ba1-xSrxFe11Cr1O19(x = 0.0 – 0.8) 六铁氧体的结构、磁性、介电和铁电性能的影响

摘要 通过共沉淀技术制备了锶取代的六铁酸钡，即 Ba 1 - x Sr x Fe 11 Cr 1 O 19，其中 x = 0.0–0.8。通过 X 射线衍射证实了所有样品的单相磁铅石结构，而扫描电子显微镜显示 Sr2+ 取代时微观结构的变化。磁性测量表明，对于 x = 0.4 的样品，替代导致饱和磁化强度和矫顽场的显着增强。然而，在相同条件下，通过阻抗谱观察到介电常数、介电损耗角正切和交流电导率的实部下降，而这些参数在 x > 0.4 时开始增加。由于 Maxwell-Wagner 界面极化，介电常数表现出与频率相关的色散行为，而制备的样品获得了弱铁电滞后回线。此外，发现 Sr2+ 取代显着增强了电阻特性，这在由于 Fe 3 + - O - Fe 2 + 网络和微观结构变化的减少而导致的电荷载流子迁移率的定位方面得到阐明。在这里，建议 x = 0.4 样品表现出最大磁化强度 (64 emu/g)、低频介电常数的中等实部 (>103)、减小的介电损耗角正切 (~0.05) 和巨大的电阻值 (~1010 Ω)，这使得这种材料对高频应用很有吸引力。结果表明，由于 Fe 3 + - O - Fe 2 + 网络和微观结构变化的减少，Sr2+ 取代显着增强了电阻特性，这在电荷载流子迁移率的局部化方面得到了阐明。在这里，建议 x = 0.4 样品表现出最大磁化强度 (64 emu/g)、低频介电常数的中等实部 (>103)、减小的介电损耗角正切 (~0.05) 和巨大的电阻值 (~1010 Ω)，这使得这种材料对高频应用很有吸引力。结果表明，由于 Fe 3 + - O - Fe 2 + 网络和微观结构变化的减少，Sr2+ 取代显着增强了电阻特性，这在电荷载流子迁移率的局部化方面得到了阐明。在这里，建议 x = 0.4 样品表现出最大磁化强度 (64 emu/g)、低频介电常数的中等实部 (>103)、减小的介电损耗角正切 (~0.05) 和巨大的电阻值 (~1010 Ω)，这使得这种材料对高频应用很有吸引力。