Paper Title
Structural and Magneto-Transport Properties of La0.7ca0.3-Xsrxmno3 (X = 0, 0.02, 0.04, 0.06, 0.08, 0.10) at Sintering Temperature Of 1120 �C

Abstract
The structural and magneto-transport properties of La0.7Ca0.3-xSrxMnO3 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) at sintering temperature of 1120 ֯C have been investigated. The sample were prepared by CO-precipitation method and sintered at 1120 ֯C. X-Ray Diffraction patterns show that the sample have an orthorhombic structure with Pbnm space group. The insulator metal transition ( TIM) increase linearly from 248 K to 292 K with the increasing of strontium doping concentrations. The percentage of magnetoresistance (MR) increased with the increasing of magnetic field (0.1 to 1 T) and strontium doping concentration for all the samples except for x = 0.10. The electrical resistivity data were fitted with several equations in the metallic (ferromagnetic) regime. The density of states at Fermi level N(EF) and the activation energy (Ea) of electron hopping were estimated by using variable range hopping and small polaron hopping model. Keywords: Activation Energy, Electrical Resistivity, Magnetotransport, Strontium.