The synthesis and magnetoresistance behavior of direct current magnetron sputtering thin film of La 0.7Pb 0.3MnO 3-δ

Abstract

The epitaxial La 0.7Pb 0.3MnO 3-δ films are synthesized on (001), (110) and (111) LaAlO 3 single crystal substrates with the direct current magnetron sputtering technique. The influence of the deposition conditions (substrate temperature and orientation, and sputtering gas pressure) on the value of metal-semiconductor transition temperature are studied systematically. It is concluded that the higher substrate temperature (≥820°C) and the moderate gas pressure (7∼9 Pa) are beneficial to the growth of high quality film and the entrance of oxygen. The magnetoresistance behavior of the as-grown films is strongly dependent on the deposition conditions. The colossal magnetoresistance (CMR) at 235 K and 0.6 T with 30% was observed in (110) orientated substrate under 9 Pa sputtering gas pressure and substrate temperature of 820°C.