Optical and magnetooptic researches of the symmetry of electronic states in TbAlO3

Full text: The magnetic susceptibility, the polarized-optical absorption spectra, and the Verde constant V along the crystallographic [110] axis of the orthorhombic crystal TbAlO3 have been investigated experimentally in the temperature interval 78 - 300 K. It is found that, in contrast to the temperature dependence of the magnetic susceptibility measured along the [110] axis, the inverse magnitude of the Verde constant varies by proportional to the temperature T in the given range. It is shown that, similar behavior of the temperature dependence of the Verde constant measured along the [110] axis is connected with the absence of a contribution to the Faraday effect of the Van-Vleck mechanism of mixing (in an external magnetic field H) of the electronic states of the rare-earth (RE) ion Tb3+ in the orthoaluminate structure. From a comparison of the data of the polarized-optical absorption and magnetooptic measurements, we have determined the symmetry and wave functions the some lowest Stark singlets for the excited 5D4 and ground 7F6 multiplets of the Tb3+ ion in the orthoaluminate TbAlO3. (authors)