Pulsed-laser-deposited epitaxial Sr2FeMoO6−y thin films: Positive and negative magnetoresistance regimes

Epitaxial thin films of ordered double-perovskite ${\mathrm{Sr}}_{\mathrm{2}}{\mathrm{FeMoO}}_{\text{6−y}}$ are deposited on (001) ${\mathrm{SrTiO}}_{\mathrm{3}}$ substrates by pulsed-laser deposition using a two step growth process. Selection of growth conditions is found to lead to either highly conductive metallic thin films (residual resistivity of about 1 μΩ cm) or semiconducting films. The metallic films show a positive magnetoresistance (MR) as high as 35%, while the semiconducting films show a negative MR of −3%, at a temperature of 5 K and a field of 8 T.