Defect models of two tetragonal Ce3+ centers T1 and T2 in Ce3+-doped cubic fluorperovskites KMgF3 and BaLiF3

摘要: Abstract The EPR g factors g|| and g⊥ for two tetragonal Ce3+ centers T1 T2 in Ce3+-doped cubic fluorperovskites KMgF3 BaLiF3 are calculated from the complete diagonalization (of energy matrix) method (where all Kramers doublets within ground excited multiplets 2F5/2 2F7/2 contained). calculations show that simple of calculating only multiplet considered) used previous papers cannot give correct signs crystal-field parameter B 2 0 hence reasonable defect models these (in fact, physically, inconsistent). new consistent suggested as follows: KMgF3:Ce3+, substitution K+ with a nearest interstitial F− and, respectively, without vacancy (VK) along C4 axis, BaLiF3:Ce3+, Ba2+ with, axis because charge compensation. Based on by considering orbit reduction effect due to covalence Ce3+–F− bonds, explained reasonably. results particular, approximations structural data centers) discussed.