The study of chromium borate CrBO3 by optical and IR spectroscopy

A complex study of the CrBO3 single crystal has been performed by optical and IR spectroscopy methods over a broad temperature range. Factor-group and correlation analyses of the phonon modes are presented. All IR active phonons and their frequencies are experimentally identified by way of attenuated total reflectance. A magnetic phase transition at a temperature of 6 K is detected. In the magnetically ordered state, an anisotropy of the optical spectrum was observed during polarization studies in the isotropic ab-plane of the crystal. A study of the temperature dependences of the phonon spectrum did not show any anomalies over the course of magnetic ordering, which indicates that there is an absence of an appreciable spin-lattice interaction in CrBO3.