Preparation and monte carlo simulation of La_0.67Ca_0.33MnO₃/Cr₂O₃ composites

Abstract

The (1−x) La_0.67Ca_0.33MnO₃(LCMO)+x Cr₂O₃ composites were synthesized by a new liquid phase method. The XRD and SEM measurements reveal that few Cr₂O₃ were soluble in the LCMO structure and the lattice constant of LCMO almost did not change, while most Cr₂O₃ were distributed at the grain boundaries or on surfaces of the LCMO grains. In resistivity versus temperature measurements, a metal-insulator transition was observed when x<0.20. The resistivity increases and the metal-insulator transition temperature decreases with the increasing content of Cr₂O₃. A random resistor network (RRN) model was used to simulate the transport property of the mixture samples. The simulation results agree with the experimental observations. The results show that the method is reasonable for understanding the electronic transport of the composites of the maganite.

Keywords

manganite / composite / random resistor network / Monte Carlo method

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