Effects of Strain in Highly Ordered Sr$_{2}$CrReO$_{6}$ Epitaxial Films*

Sr$_{2}$CrReO$_{6}$, a double-perovskite ferrimagnet, has attracted much attention because of its Curie temperature well above room temperature and predictions of half-metallicity. We have deposited pure-phase Sr$_{2}$CrReO$_{6}$ epitaxial films on several (001)-oriented substrates and buffer layers by ultrahigh vacuum off-axis magnetron sputtering, in order to study tensile and compressive strain effects due to lattice mismatches up to 1.5{\%}. Triple-axis x-ray diffractometry was used in tandem with direct observations via HAADF STEM to confirm film epitaxy, phase purity, Cr/Re ordering, and strain via film lattice constants. Magnetic characterization shows a marked effect on the saturation magnetization due to strain, with slight changes in the Curie temperatures. Finally, electrical and optical characterization suggest that Sr$_{2}$CrReO$_{6 }$is a gapped material under both unstrained and strained systems, and will be discussed in detail as well.