Transport Properties and Magnetoresistance of La_(0.8)Ca_(0.13)Ag_(0.17)MnO3 Perovskite Manganite Synthesized by Sol-Gel Method

摘要

In this paper,we investigate the transport properties and magnetoresistance effect of La_(0.8)Ca_(0.13)Ag_(0.07)MnO3 perovskite manganite synthesized by sol-gel method.The XRD pattern of the sample shows a rhombohedral perovskite structure with space group R3c.The EDX analysis confirms that the sample contains all expected chemical elements without any additional impurity.The temperature dependence of electrical resistivity was measured using a cryogenic magnetometer.The results show a metal-insulator transition temperature(T_(M-I))at 280 K.The resistivity of the sample increases with an increase of temperature below 7m-/.Theoretical analyses of the temperature dependence of resistivity suggest that the resistivity due to electron-electron scattering is predominant below T_(i-m)The resistivity of the sample decreases when applied magnetic field 1 T at a temperature range of 10 K to 300 K.The magnetoresistance of La_(0.8)Ca_(0.13)Ag_(0.07)MnO3 emanates from spin-polarized tunneling process at the grain boundary.