Low dc leakage Cr$_{\mathrm{2}}$O$_{\mathrm{3}}$ thin films towards mili-volt switching of exchange bias*

Reactive bias target ion beam deposition (RBTIBD) was used to synthesize single phase highly textured antiferromagnetic Cr$_{\mathrm{2}}$O$_{\mathrm{3}}$ on Pt/sapphire substrate. The as-deposited substrate temperature and oxygen flow rate were explored to optimize the phase, crystallinity, and surface morphology of the Cr$_{\mathrm{2}}$O$_{\mathrm{3\thinspace }}$thin films with Neel temperature of 300 K. A very low electric leakage (3E-5 A/cm$^{\mathrm{2}})$ in single-phase chromia films less than 10 nm thick was observed. Dielectric permittivity and loss were measured as a function of film thickness. These new results demonstrate the potential of milli-volt switching voltage for exchange bias of magnetic structures using antiferromagnetic chromia, for practical low power switching of magnetic tunnel junctions.