Effects of Cr,Co,Ni substitution at Mn-site on structural, magnetic properties and critical behaviour in Nd0.67Ba0.33MnO3 mixed-valent manganite

Abstract

This work investigates on the crystal structure, magnetic nature and critical behaviour with the partial replacement of transition (Tr) elements (ie., 10% of Cr, Co, Ni) at the Mn-site of Nd0.67Ba0.33MnO3 (NBMO) synthesised via conventional solid-state-method. NBMO compound is crystallised into an orthorhombic crystal structure and possess a magnetic transition temperature (Tc) at 145 K. Crystal structure of NBMO remains the same with partial substitution of Tr elements but, the Tc is found to be slightly increased with the doping of Cr, while decreases with the doping of Co and Ni. The magnetic isotherms are traced, and critical exponents are studied using modified Arrott plots (MAP) and power law. All the substituted samples show a second-order nature of Tc similar to that of the parent compound. The critical parameters are identified and verified through MAP, critical isotherms, Kouvel-Fisher method and field dependence of entropy change. All the substituted compounds govern the 3D Heisenberg with short-range order.