Paramagnetic Resonance of Chromium in MgTiO3

The paramagnetic resonance spectrum of ${\mathrm{Cr}}^{3+}$ in single crystals of rhombohedral MgTi${\mathrm{O}}_3$ was measured at frequencies of 24 kMc/sec and 35 kMc/sec. The results indicate that ${\mathrm{Cr}}^{3+}$ is located at ion sites of trigonal symmetry. The spectrum can be described by an axial spin Hamiltonian with $S=\frac{3}{2}$. The parameters at room temperatures are: $\mathrm{}\left|D\right|=(15.05\mathrm{}\pm 0.03)$ kMc/sec, $g_{\mathrm{II}}=1.976\mathrm{}\pm 0.002$, $g_{\perp }=1.981\mathrm{}\pm 0.002$. Due to the relatively large zero-field splitting, the chemical stability and good mechanical properties, chromium-doped MgTi${\mathrm{O}}_3$ might be a useful material for solid-state masers.