Theory of the Raman and Brillouin Scattering on the Excited Electronic States and Magnons in Europium Chalcogenides

Recently considerable progress has been made in the investigations of the excited electronic states by using the Raman spectroscopy[1]. In the present paper we examin the possibility of applying of this method in the measurement of the electronic properties of magnetic semiconductors. Among those the europium chalcogenides seem to be of particular interest for the following reasons: a) the free Eu2+ ion is in the orbital singlet state and the structure of the 4f band is very simple, b) the optical absorption data are well explained on the basis of the d-f exchange model proposed by GUNTHERODT, WACHTER and IMBODEN [2,3],which will be called GWI model throughout the paper. On the other hand, the absorption and reflection experiments don’t give information about the internal structure of the electronic bands, values of the d-f exchange integral and spin orbit coupling in the 5d multiplet. In the present paper we show that electronic Raman processes and onemagnon Brillouin scattering may be useful sources of such information.