EPR study of fluorite containing different concentration of ceria

Abstract The variation of EPR spectra has been investigated in CaF2 single crystals doped with ceria depending on the content of CeO2 and methods of the crystal growth. The concentration of CeO2 changed from 0.5% CeO2 up to 15% CeO2. For the low concentrations of CeO2 the spectra are mainly due to the usual tetragonal or trigonal EPR centers. For the sample with 5 at% CeO2 grown in argon atmosphere by the Bridgman technique the alternative tetragonal center with g|| = 0.73, and g┴ = 2.6 prevails. The possible models of EPR centers are briefly described.