Orbitally correlated crystal field parametrization for lanthanide ions

Abstract

Analogous to the treatment of the spin-correlated crystal field, a new type of lanthanide correlation crystal field, which depends on the relative orientations of the individual 4f electron orbital angular momenta and the total orbital angular momentum, is postulated. Associated sets of parameters have been obtained for TmCl3⋅6H2O, Er3+:LaCl3, and Pr3+:LaCl3 from the quadratic moments of the J-multiplet energy levels. The results show that this field is noticeable in the Pr3+:LaCl3 spectrum in which the particularly well known deviance of the 1D2 multiplet found in conventional crystal field fitting is largely eliminated.