Electrical transport and magnetoresistance in La2/3Ca1/3MnO3/BaZrO3 composites

We report the results of electrical resistivity and magnetoresistance (MR) measurements carried out on La2/3Ca1/3MnO3/BaZrO3 composites prepared by solid state reaction method. The metal-to-insulator transition and the magnitude of magnetoresistance are significantly influenced by the content of BaZrO3, suggesting the presence of ionic diffusion between La2/3Ca1/3MnO3 and BaZrO3, although the dependence of the electrical resistivity as a function of La2/3Ca1/3MnO3 volume fraction can be roughly described by classical percolation conduction model. The conductive behavior above the metal-to-insulator transition temperature can be well explained by Mott's variable range hopping model. (C) 2012 Elsevier B. V. All rights reserved.