EPR study of Gd3+ in a ferroelastic BiVO4 single crystal

Electron paramagnetic resonance of the Gd3+ ion in a ferroelastic BiVO4 sin gle crystal with a single domain, grown by the Czochralski method, has been investigated at room temperature using a Q-band spectrometer. The rotation patterns of the resonance fields measured in the crystallographic planes a re analyzed using a monoclinic spin Hamiltonian. The principal Z-axis of th e second-order zero-field splitting tensor D is found to be along the cryst allographic b-axis. Spin Hamiltonian parameters together with the principal axes of g and D tensors in the monoclinic plane show that the local site s ymmetry of Gd3+ ion in BiVO4 crystal is monoclinic and that the Gd3+ ion su bstitutes for Bi3+ ion.