Effect of A-site cation size on the structural, magnetic, and electrical properties of La1−xNdxMn0.5Cr0.5O3 perovskites

A systematic investigation of rare earth chromium manganites with general formula La1−xNdxMn0.5Cr0.5O3 (x = 0.0, 0.3, 0.6 and 0.9) has been undertaken mainly to understand their structural, magnetic as well as electrical behavior. Upon Nd doping on La site, unit cell volume and the B-O-B bond angle are reduced. The magnetic interactions in the materials are predominantly ferromagnetic and we believe that double exchange interactions between Mn3+ and Mn4+, and Mn3+ and Cr3+ should be the origin of ferromagnetism. The Curie temperature decreases with increasing Nd content. All the samples are semiconducting throughout the temperature range studied. The electric transport behavior can be described by the adiabatic small polaron hoping model, with an apparent increase of polaron activation energy with Nd content.