Second and fourth order spin-lattice coefficients for Gd 3+ in theoria.

Abstract

In this work we tried successfully to measure the fourth order coefficients of H' for Gd3+ in ThO2. This system was chosen because its small EPR linewidths (about 1 gauss) allows precise measurements of the lineshifts. We used a conventional 35 GHz EPR Spectrometer with provisions to apply uniaxial stress on the sample. The stress system was carefully designed and built in order to minimize the changes of the position of the sample with stress 4..