Bismuth centred magnetic perovskite: A projected multiferroic

Abstract

Abstract In recent time substantial attention has been initiated to understand the physics behind multiferroism and to design new multiferroic materials. BiMnO 3 and BiFeO 3 are the well-studied Bi-centred multiferroic oxides. BiMnO 3 is a ferromagnetic–ferroelectric (metastable) phase and require drastic conditions to synthesize. However, lanthanum substituted BiMnO 3 phases stabilized at ambient pressure. It is thus of major importance to increase the number of ferromagnetic perovskites with Bi cations that could be designed under ambient conditions. In this article, we have presented an up to date report of investigations on Bi-centred magnetic perovskites, a prospective material for multiferroic application. Central focus is concentrated on La 0.5 Bi 0.5 MnO 3 perovskite with various substitutions at different levels. A few of these perovskites are found to be of practical importance e.g. La 0.5 Bi 0.5 Mn 0.67 Co 0.33 O 3 with high dielectric permittivity coupled with ferromagnetism. A comprehensive analysis of different physical functionalities and their interrelation for a wide range of compositions of these Bi-centred perovskites is presented. It has been found that the complex magnetic behaviour originates from mixed valence metal ions. The ferroelectricity is associated with the 6 s 2 lone pair of Bi 3+ cations. The magnetic ground state influences the dielectric properties reflecting the multiferroism in a single material.