Multiferroic composite with the general formula (1 − x )BaTiO 3 − x CoFe 2 O 4 ( x = 0.05, 0.15, 0.25, 0.35 and 0.45) has been synthesized by a standard solid-state reaction route. Powder X-ray diffraction analysis confirms the existence of ferrite (spinel CoFe 2 O 4 ) and ferroelectric (tetragonal BaTiO 3 ) biphase without any impurity phases in the sintered composites. Microstructure of the composite displays two different grain sizes and shapes studied from SEM analysis. The composites show both ferroelectric and ferromagnetic ordering: the saturation magnetization ( M s ) and retentivity ( M r ) of the composite are improved with the increase in ferrite phase, while leakage current, ferroelectric and dielectric properties of the composites show a drop. Existence of coupling between ferroelectric and ferromagnetic ordering measured through magnetodielectric (MD) and magnetoelectric (ME) studies reveal an increase in % MD and ME coefficients with an increase in ferrite content. An enhanced ME coupling coefficient of 17 mV cm −1 Oe −1 has been realized at a dc magnetic field of 5 kOe with a ac frequency of 50 Hz in (1 − x )BaTiO 3 − x CoFe 2 O 4 ( x = 0.45) composite.

中文翻译：

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(1 − x)BaTiO3−xCoFe2O4 颗粒复合材料的组成相关的结构、电、磁和磁电特性

通式为 (1 - x )BaTiO 3 - x CoFe 2 O 4 (x = 0.05, 0.15, 0.25, 0.35 和 0.45) 的多铁性复合材料已通过标准固态反应路线合成。粉末 X 射线衍射分析证实在烧结复合材料中存在铁氧体（尖晶石 CoFe 2 O 4 ）和铁电体（四方 BaTiO 3 ）双相，没有任何杂质相。复合材料的微观结构显示出从 SEM 分析中研究的两种不同的晶粒尺寸和形状。复合材料表现出铁电和铁磁两种有序性：复合材料的饱和磁化强度（Ms）和保持率（Mr）随着铁氧体相的增加而提高，而复合材料的漏电流、铁电和介电性能下降。通过磁介电 (MD) 和磁电 (ME) 研究测量的铁电和铁磁排序之间存在耦合，表明随着铁氧体含量的增加，MD 和 ME 系数的百分比增加。在 (1 - x )BaTiO 3 - x CoFe 2 O 4 (x = 0.45) 中，在 5 kOe 的直流磁场和 50 Hz 的交流频率下实现了 17 mV cm -1 Oe -1 的增强 ME 耦合系数） 合成的。