Electron Tunneling Cr-Cr2O3-Metal Junctions

Conductance measurements on high-quality thin-film Cr-${\mathrm{Cr}}_2$ ${\mathrm{O}}_3$-metal tunnel junctions show neither structure due to the antiferromagnetic energy gap of bulk Cr nor zero-bias anomalies. The conductance is almost linear in voltage at low temperatures and biases, with fine structure at 28, 44, 62, and 82 meV. These results are in qualitative agreement with the assumption of inelastic tunneling via elementary excitations of the ${\mathrm{Cr}}_2$ ${\mathrm{O}}_3$ barrier.