Multiferroic nanoparticles of manganese doped bismuth ferrite with the chemical formula, Bi 1- x Mn x FeO 3 , with x values of 0, 0.025, 0.05, 0.075 and 0.1, were synthesized by sol–gel autocombustion method. X-ray diffraction measurements and Rietveld structural refinements were performed on the samples to ensure the formation of rhombohedrally distorted perovskite phase for all the samples. Dielectric measurements of the samples have been carried out in a wide range of frequencies from 1 to 40 MHz and at different temperatures in the range from 30° to 450 °C. Temperature-dependent dielectric anomalies were observed and the same were attributed to structural inhomogeneities at around 150°–270 °C, and to typical free charge carrier hopping mechanisms and anomalies at around 270°–420 °C. Impedance analysis of the samples provides indirect support for the reasons discussed in the dielectric properties and the corresponding electrical conductivity behaviour in these samples. Magnetic measurements were carried out to understand the influence of Mn ions on the magnetic behaviour of the studied multiferroics. The results of all these measurements are well discussed, and they indicate a considerable enhancement in the magnetic order with Mn doping and also a decrease in the dielectric loss with an evidence magnetoelectric coupling and thus making them useful for device applications.

中文翻译：

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Mn掺杂的铋铁氧体多铁性纳米陶瓷的介电和磁性能增强

通过溶胶-凝胶自燃法合成了锰掺杂的铁氧体铋的多铁性纳米粒子，其化学式为 Bi 1- x Mn x FeO 3 ，x 值为 0、0.025、0.05、0.075 和 0.1。对样品进行 X 射线衍射测量和 Rietveld 结构改进，以确保所有样品都形成菱形扭曲的钙钛矿相。样品的介电测量已在 1 至 40 MHz 的广泛频率范围内和 30° 至 450 °C 范围内的不同温度下进行。观察到与温度有关的介电异常，这归因于约 150°–270 °C 的结构不均匀性，以及约 270°–420 °C 的典型自由电荷载流子跳跃机制和异常。样品的阻抗分析为这些样品中介电特性和相应的电导率行为中讨论的原因提供了间接支持。进行磁测量以了解 Mn 离子对所研究的多铁性材料的磁行为的影响。所有这些测量的结果都得到了很好的讨论，它们表明掺杂 Mn 后磁序显着增强，并且介电损耗降低，磁电耦合明显，从而使它们可用于器件应用。进行磁测量以了解 Mn 离子对所研究的多铁性材料的磁行为的影响。所有这些测量的结果都得到了很好的讨论，它们表明，随着 Mn 掺杂，磁序有相当大的增强，并且随着磁电耦合的出现，介电损耗也有所降低，从而使它们可用于器件应用。进行磁测量以了解 Mn 离子对所研究的多铁性材料的磁行为的影响。所有这些测量的结果都得到了很好的讨论，它们表明掺杂 Mn 后磁序显着增强，并且介电损耗降低，磁电耦合明显，从而使它们可用于器件应用。