Energy Levels of Gd^3+ in Five Hexagonal Crystals*

Abstract

The optical absorption spectra of 1% Gd:LaBr3, 5% Gd:LaCl3, GdCl3, 2% Gd:Y(OH)3 and Gd(OH)3 at 1.5 K in high resolution are given over the region 31 000 cm−1 to 41 000 cm−1. Reduced matrix elements based on intermediate-coupling free-ion calculations are used to perform a crystal-field analysis for Gd3+ in a 6¯(C3h) symmetry electrostatic field. A least-squares fit to levels in each crystal has led to the assignment of M quantum numbers to most levels and of Bkq parameters to each crystalline host.