Annealing Effect on Transport and Magnetic Properties of La0.67Sr0.33MnO3 Thin Films Grown on Glass Substrates by RF Magnetron Sputtering

The manganite La0.67Sr0.33MnO3 (LSMO) thin films were grown on glass substrates in a mixed argon and oxygen atmosphere by using RF magnetron sputtering. The structural characteristics, transport behaviors and magnetic properties of LSMO films were studied by annealing the films in air at 550 and 620°C. The out-of-plane lattice parameter aLSMO contracted after annealing and was close to that of bulk LSMO abulk, indicating that the internal strain was fully relaxed. Nanocrystalline grains were observed in the annealed films. Enhanced saturation magnetization and metal-to-insulator transition temperature (TMI=268 K) were also obtained. Curie temperatures (Tc) of the as-grown films was 340 K with the same as that of annealed at 550°C, but dropped to 315 K when the annealing temperature increased to 620°C, which can be attributed to the oxygen release during annealing in atmosphere.