Crystal-field spectra of trivalent holmium in HoVO4, HoAsO4, HoPO4 and Y(OH)3 in the infrared region

The polarized absorption spectra of Ho3+ in HoVO4, HoAsO4, HoPO4 and (Ho0.1,Y0.9) (OH)3 were studied in the range from 5000 to 12000 cm-1. Nearly all crystal-field components were found and their crystal quantum numbers mu , nu and S could be assigned.