Spectroscopic investigation of holmium vanadate, HoVO₄

Abstract

Spectroscopic investigation into the properties of HoVO4 has revealed interesting and unusual anomalies. These centre on the fact that the first excited doublet (at 21 cm-1) shows a small (2.3 cm-1) zero-field splitting at low temperatures. Although no phase transition has been detected in HoVO4, it is concluded from the experimental data that the splitting is real enough and that the symmetry at the Ho3+ site must be lower than tetragonal. A number of effects which might be responsible for this splitting are investigated, but the origin of the splitting remains obscure.