ESR of V4+ions in α-berlinite AlPO4

The X-band ESR spectrum of vanadium-doped alpha -berlinite AlPO 4 has been observed at room temperature. The spectrum, attributed to V 4+ in a distorted tetrahedral site, can be described by a spin Hamiltonian of axial symmetry. The Hamiltonian parameters are: g/sub ///=1.9278, g perpendicular to =1.9759, mod A/sub /// mod =175*10 -4 cm -1 , mod A perpendicular to mod =66*10 -4 cm -1 . The wavefunction of the ground state is of the d x-y type (where x-y=x 2 -y 2 ).