Enhanced dielectric and magnetic properties in Mn-doped bismuth ferrite multiferroic nanoceramics

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.