The determination of crystal field parameters in rare earth intermetallic compounds

The behavior of the 4f systems is strongly influenced by the crystal field interaction as is evidenced in most of their magnetic properties. A systematic analysis of these properties can thereby be used to extract general trends for the determination of this fundamental interaction through the crystal field parameters. Although for cubic systems it is sufficient the information provided by the inelastic neutron scattering method, in low symmetry systems a single experiment is not usually enough, due to the large number of parameters involved in the problem that often leads to several admissible possibilities. In order to determine without ambiguity the crystal field parameters it is then necessary to consider the information drawn from different magnetic properties in a self-consistent way. To illustrate these ideas some selected examples in tetragonal REAg2 and RENi2Si2 systems will be presented and discussed. (orig.)