Measurement of Spin Coherence Times in Proton Irradiated 4H-SiC

Silicon vacancy defects in silicon carbide (SiC) have potential for use in spintronic devices. We used optically detected magnetic resonance and a spin echo technique to measure T$_{\mathrm{2}}$ spin coherence times for electrons in 4H-SiC. These experiments were performed at a magnetic field strength of 0.371 T and a resonant microwave frequency of 10.5 GHz. Each sample contained silicon vacancy defects that were formed through irradiation with 2 MeV protons at unique fluences (10$^{\mathrm{13}}$ and 10$^{\mathrm{14}}$ cm$^{\mathrm{-2}})$. Measurements for each sample were made across a range of temperatures, from 8 K to room temperature. While we generally observed a decrease in spin coherence time with temperature, we also observed a range of temperatures (from 60 K to 160 K) for which the overall trend was reversed.