Magneto-optical spectra and electron structure of Nd 0.5 Gd 0.5 Fe 3 (BO 3 ) 4 single crystal

Abstract Polarized absorption spectra and magnetic circular dichroism (MCD) spectra of Nd 0.5 Gd 0.5 Fe 3 (BO 3 ) 4 single crystal were measured in the range of 10000–21000 cm −1 and at temperatures 2–300 K. On the basis of these data, in the paramagnetic state of the crystal, the 4 f states of the Nd 3+ ion were identified in terms of the irreducible representations and in terms of | J , ± M J 〉 wave functions of the free atom. The changes of the Lande factor during f–f transitions were found theoretically in the | J , ± M J 〉 wave functions approximation and were determined experimentally with the help of the measured MCD spectra. In the majority of cases the experimentally found values are close to the theoretically predicted ones.