Investigation of wide range magnetoresistance in La_(0.7)Ca_(0.3-x)Ag_xMnO_3 (0 ≤ x ≤ 0.2) system

摘要

We synthesized magnetoresistive compounds with nominal compositions La_(0.7)Ca_(0.3-x)Ag_xMnO_3 (0 ≤ x ≤ 0.2) by solid state reaction method with different sintering temperatures. All the samples exhibited orthorhombic structure with variable lattice parameters. The metal-insulator transitions were observed below room temperature in most of the samples. Depending upon the composition and sintering temperature, the samples showed very high magnetoresistance in narrow range or significant magnetoresistance over wide range of temperature. The ac susceptibility measurement revealed compositional dependence of Curie temperature.