Electron Paramagnetic Resonance ofGd3+in YVO4

The EPR spectrum of ${\mathrm{Gd}}^{3+}$ in YV${\mathrm{O}}_4$ has been examined at room temperature with a K-band spectrometer. The results fit a tetragonal-spin Hamiltonian. The parameters are $g_{\parallel }=g_{\perp }=1.9916\mathrm{}\pm 0.0002$, $b_2^{}{}_{}{}^0=-441.6\mathrm{}\pm 0.2$, $b_4^{}{}_{}{}^0=-1.5\mathrm{}\pm 0.1$, $b_6^{}{}_{}{}^0=0.8\mathrm{}\pm 0.6$, $b_4^{}{}_{}{}^4=8.3\mathrm{}\pm 0.1$, and $b_6^{}{}_{}{}^4=0.0\mathrm{}\pm 0.2$ in units of ${10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$. The signs of the parameters are relative.