X-ray and gamma irradiation effects on dipole defects in CaF2CaF2: La, Yb, Al

Impurity-interstitial dipoles in calcium fluoride solutions with Al3+Al3+, Yb3+Yb3+ and La3+La3+ fluorides were studied using the thermally stimulated depolarization current (TSDC) technique. The dipolar complexes are formed by substitutional trivalent ions in Ca2+Ca2+ sites and interstitial fluorine in nearest neighbor sites. The relaxations observed at 150 K are assigned to dipoles nnRS3+– Fi- (RS=LaRS=La or Yb). The purpose of this work is to study the processes of energy storage in the fluorides following X-ray and gamma irradiation. Computer modelling techniques are used to obtain the formation energy of dipole defects.