Effect of Cr doping in Structure and Magneto-transport Properties of (La0.67Sr0.33)MnO3

Abstract

The study of perovskite manganites La_0.67Sr_0.33Mn_1-xCr_xO₃ (0? x ?0.10) has been carried out. The structure and magneto-transport properties of La_0.67Sr_0.33Mn_1-xCr_xO₃ manganites are strongly dependent on the doping level x. Polycrystalline samples of La_0.67Sr_0.33Mn_1-xCr_xO₃ (0? x ?0.10) were prepared by solid state reaction method. The little difference between the ionic radii of Cr³⁺ and Mn³⁺ causes no change in the structure, the structure remains rhombohedral. The temperature dependence of the resistivity is measured from 5 – 400 K without and with magnetic field upto 5 T. The value of metal-insulator (M-I) transition temperature (T_P) decreases when resistivity increases for all the samples while doping level x increases. The value of magnetoresistance (MR %) increases with increases Cr doping level for all samples. We have calculated energy band gap (E_g) for all samples and it is revealed that as per doping level increases E_g increases which is comparable with experimental data. So, the structure and magneto-transport behavior pretentious by Cr doping.

Keywords: Colossal magnetoresistance, metal-insulator transition.