Determination of magnetic anisotropy of complex rare-earth compounds from mossbauer and NMR spectra

Experimental data and theoretical papers on the magnetic anisotropy (MA) of rare-earth-transition metal intermetallic compounds are reviewed. Discrepa ncies between the experimental data obtained by different authors, as well as between these data and the theoretical calculations of the MA constants, are indicated. A technique is proposed for determining the crystal-field p arameters and the effective charges Q(i)* of ions in intermetallic compound s. Using experimental Mossbauer and NMR spectroscopic data, possible values of Q(i)* are determined for R2T17-x and R2T17- Ti-x(x) compounds, which al low one to find the MA constants of these systems with different R and T in a unified way. The problem of the sign of the contribution from the rare-e arth metal sublattice to the MA is discussed. The heavy x dependence of thi s contribution in the R2T17- xTix system is explained to be due to the cont ribution to the crystal field from Ti ions in the dumbbells. (C) 2001 MAIK "Nauka/ Interperiodica".