The effect of hydrostatic pressure and temperature on the EPR spectrum of the Eu2+ ion in CdF2

The effect of temperature and hydrostatic stress on the b04 spin-Hamiltonian parameter for Eu2+ in CdF2 single crystal is investigated. The measurements are carried out in X-band in the temperature range from 77 to 447 K and the pressure range up to 5000 at. The following results are obtained: (σb04/T)sub(p=1at) = -220 x 10-8 cm-1 K-1 and (σb04/σp)sub(T=300 K) =+1.66 x 10-8 cm-1 at-1. It is deduced, on the basis of these results, that about 70% of the temperature changes in b04(T) can be related to the thermal expansion of the crystal i.e. to the changes in metal-ligand distance. (author)