MAGNETOOPTICAL STUDY OF KER(MOO4)2 IN LON G-WAVE IR RANGE

The absorption spectra of KEr(MoO4)2 single crystals are measured in a long-wave IR range (14-40 cm-1) al temperatures of 4.2 and 2 K in ext ernal magnetic field. Three absorption bands of frequencies of 15.4. 2 6.0 and 30.5 cm-1 are revealed. A kink in the frequency-field dependen ce of the 15.4 cm-1 band splitting is observed at H(c) approximately 9 kOe with directing external magnetic field parallel to the axis a of the KEr(MoO4)2 crystal. It is suggested that the above singularity is responsible for the structural phase transition induced by external ma gnetic field.