Strontium-Osmium-oxide films by molecular beam epitaxy

Metallic SrO-OsO$_{\mathrm{2}}$ thin films were grown on (001)-oriented SrTiO$_{\mathrm{3\thinspace }}$and Lanthanum-Strontium-Aluminum-Tantalum (LSAT) substrates by molecular beam epitaxy as a function of substrate temperature from 480 to 650 \textdegree C. We explored the SrO-OsO$_{\mathrm{2}}$ ternary phase diagram to establish appropriate thermodynamic conditions to synthesize the possibly-superconducting Sr$_{\mathrm{2}}$OsO$_{\mathrm{4}}$ phase. X-ray diffraction showed that crystallographic phase of the resulting film depended on substrate temperature. Temperature dependent resistivity was measured by four-probe method from 300 to 4 K. The lowest room temperature resistivity achieved was 0.467 m$\Omega $-cm for a film grown at 480 \textdegree C. The resistivity achieved at 4 K was 0.480 m$\Omega $-cm. Superconducting osmate films have potential applications in quantum computers.