Matrix Elements of Crystal Electric Fields in Rare Earth Compounds

Abstract

In rare earth compounds, the crystal electric fields on the f electrons determine various physical properties, i.e., magnetic susceptibility, magnetic anisotropy, specific heat and electrical resistivity. The Stevens’ operator equivalent methods to calculate the matrix elements of crystal electric fields have been widely used because the matrix elements of operator equivalents O l have been listed in tables. 2) However, matrix elements of sineterm operator equivalents O l (s) have not been shown. Recently, ternary rare earth compounds have received much attention because of anomalous physical properties. In these compounds, sometimes the rare earth ions enter into the sites of low point-group symmetry and sine-terms appear. For example, in the -TiNiSi type CePtSn, Ce ion occupies the monoclinic Cs point-group symmetry sites and the crystal electric field potential is given by