EPR study ofFe3+impurities in crystallineBiVO4

Abstract
The electron paramagnetic resonance of an Fe3+ (S=5/2) impurity in the ferroelastic phase of a BiVO4 single crystal has been investigated. The rotation patterns of the resonance fields measured on the crystallographic planes are analyzed with the monoclinic spin Hamiltonian. The determined parameters are gxx=1.976, gxz=0.0033, gyy=1.995, gzz=1.994, and B20=467.3, B22=2339, B21=1693, B40=0.12, B41=-2.3, B42=-0.8, B43=4, and B44=-0.3 in units of the 104 cm1. The principal X, Y and Z axes of the D tensor are found to be along the crystallographic c*+30.5°, a+30.5° in the c*a plane, and b axis, respectively. The zero-field splitting (ZFS) parameters D and E are calculated both within the point-charge electrostatic model and the superposition model. Comparison of experimental data with calculated second-order axial and rhombic ZFS parameters suggests that the Fe3+ impurity substitutes for the V5+ ion in BiVO4. © 1996 The American Physical Society.