Effect of the deposition temperature on the low-field magnetoresistance of polycrystalline La0.5Sr0.5MnO3 thin films produced by pulsed laser deposition

Abstract

Pulsed laser deposition of La0.5Sr0.5MnO3 (LSMO) thin films on quartz wafers at different deposition temperatures has been carried out. The microstructural, electrical and low-field magnetotransport properties of these films are evaluated as functions of the deposition temperature. The film crystallinity depends substantially on the deposition temperature. Significantly enhanced low-field magnetoresistance for the samples deposited from 570 °C to 600 °C, in which amorphous phase and polycrystalline phase coexist, is observed. The electrical and low-field magnetotransport properties of the thin films are explained by the two-channel model where insulating channels of variable-range-hopping conduction and metallic ones coexist.