Magnetic Properties of SmCrO3 and GdCrO3 Based Bulk Orthochromites

Abstract

This thesis present the structural, magnetic and dielectric properties of interesting orthochromites such as SmCrO3 and GdCrO3 by substituting transition elements, Mn and Fe at the Cr site and Y at Gd site. The samples were prepared in single phase form using the solgel route and the prepared samples are found to crystallize in orthorhombic structure with Pbnm space group. All samples of SmCr1-xMxO3 (M = Mn or Fe) series exhibit antiferromagnetic (AFM) transition with an exception of SmCr0.50Mn0.50O3 having ferromagnetic (FM) transition at TC = 70 K. In Mn substituted SmCrO3 compounds interesting temperature induced magnetization reversal (MR) is observed for x = 0.10 - 0.30 samples with magnetic compensation temperature (Tcomp) increasing from 51 K (x = 0.10) to 126 K (x = 0.30) whereas in case of Fe substitution, the magnetization reversal is observed only for x = 0.10 and x = 0.15 samples with a higher Tcomp of 75 K and 148 K respectively. Similarly, in GdCr1-xMxO3 (Mn or Fe) the temperature induced magnetization reversal is observed for x = 0, 0.05, 0.40 and 0.50 samples for Mn substitution whereas the magnetization reversal is found to be suppressed upon Fe substitution.