Thin films of double perovskite Sr[sub 2]FeMoO[sub 6]: Growth, optimization, and study of the physical and magnetotransport properties of films grown on single-crystalline and polycrystalline SrTiO[sub 3] substrates.

Thin films of Sr[sub 2]FeMoO[sub 6] have been deposited on single-crystalline and polycrystalline SrTiO[sub 3] substrates by pulsed laser deposition from a stoichiometric target. In order to obtain high-quality films, the deposition parameters were systematically optimized. The films grown under optimized conditions show properties comparable to those of bulk Sr[sub 2]FeMoO[sub 6] single crystals. Surprisingly, polycrystalline films obtained by depositing on polycrystalline SrTiO[sub 3] substrates do not show any significant low-field magnetoresistance (MR), contrary to expectations for a spin-polarized material. However, after controlled annealing-induced alteration of the grain-boundary properties, a development of the low-field MR feature is clearly observed. The occurrence of the low-field MR is accompanied by nonlinearity in the current-voltage characteristics. These results are analyzed in the light of the prevalent understanding of the properties of this double perovskite material. [ABSTRACT FROM AUTHOR]