Studies on Local Structural Inhomogeneity and Origin of Ferroelectricity in Yttrium chromite Ceramics

YCrO 3 (YCO) is known to be a multiferroic with orthorhombic, Pnma , structure with center of inversion. However, the local structural inhomogeneity in this compound is believed to give rise to ferroelectric behavior. In this study we explore high temperature Raman investigations of YCO and observed that one of its Raman mode B 3g (3) (CrO 6 Octahedral tilt mode) softens around the structural phase transition which could be the origin of ferroelectric nature in YCO. In addition, we substitute bismuth (Bi) in YCO to understand the structural distortions that lead to local structural inhomogeneity. Besides B 3g (3) mode softening with composition and high temperature studies in Y 1-x Bi x CrO 3 the study reveals the structural distortions and the structural tunability Bi offers in such systems.