Evidence of two tetragonal phases in nano-BF-xPT (x=0.4) powder and its effect on magnetic properties

Abstract

Nano-Crystalline powder of 0.6BiFeO3-0.4PbTiO3 solid solution was synthesized by sol-gel method. It is already being reported that bismuth ferrite (BiFeO3) is one of the most favourable multiferroic materials which show Curie temperature and Néel temperature, both are well above the room temperature. This raise the possibility of developing new kinds of devices based on coupling of magneto-electric at room temperature. The magneto-electric coupling is an interesting phenomenon where cross-coupling exists between electric and magnetic interactions. This kind of coupling is very important from the applications point of view for developing new generation multifunctional sensor, actuator and data storage devices. The synthesis has been successfully achieved by using maleic acid as chelating agent. The calcinations of gel at 550 °C yielded pure BF-0.4PT powders, with average particle size of 40nm as determined using scanning electron microscopy (SEM). Rietveld analysis of room temperature x-ray diffraction data of BF-0.4PT shows that the system has two tetragonal phases with tetragonality of 8.82% and 1.18%. Room temperature M-H measurement reveals exchange bias of ~100 Oe, which confirms core-shell type structure present in nano BF-0.4PT powder. © 2021 Author(s).