EPR Study of Local Position for Fe³⁺in Layer Oxide Bi₂WO₆

Abstract

EPR measurements have been made on a Fe 3+ centre in single crystals of Bi 2 WO 6 at room temperature using X-band spectrometer. The fine structure interaction is much stronger than the Zeeman interaction and the principal ζ-axis of the second-rank fine structure tcnsor is close to the direction of the crystalline layer axis ( b -axis). It is found from superposition-model analyses of the fine-structure parameters that the Fe 3+ ion substitutes for a Bi 3+ ion. The large magnitudes of the parameters b 2 0 =1.40(1), b 2 1 =-0.36(1), b 2 2 =-0.09(1), b 2 -1 =0.34(1) and b 2 -2 =0.23(1) cm -1 obtained in the ( cab )-coordinate system are explained by a deviation of Fe 3+ ion mainly along the b -axis, so the piramidal structure of the centre in Bi 2 O 2 layer is flattened from that of host crystal.