Effect of Thermal Annealing on Structural, Electrical, and Magnetic Properties of Ag-doped La_(0.67)Ca_(0.33)MnO_3 Thin Films Grown on LaAlO_3 Substrates

摘要

Resistance as a function of temperature showed that the metal-insulator transition temperatures of as-grown and annealed Ag-doped La_(0.67)Ca_(0.33)MnO_3 thin films were 235 and 300 K, respectively, and that the metal-insulator transition ranges of these films were relatively narrow, indicative of a sharp phase transition. The temperature coefficient of resistance was as high as 8% at 276 K. The magnetoresistance ratio of the annealed Ag-doped film under a magnetic field of 5 T was approximately 55% at 285 K.