A combination of critical experiments has been carried out in order to elucidate the recent conclusions of Bradbury and Wong, who attributed all the dominant KCl: Sm2+ fluorescence lines to the nearest-neighbor C2v(1,1,0)Sm2+−K+ vacancy site. In an extensive investigation into the radiationless quenching, characteristic lifetimes, excitation spectra, and Zeeman polarization of KCl: Sm2+ fluorescence lines, all the prominent lines are unequivocally attributed to a distribution of three different Sm2+ - K+ vacancy sites. In addition, 18 weak lines are shown to originate from dimeric cluster and O2− compensated sites. The paradoxical C2v interpretations of Bradbury and Wong are shown to be based on incorrect premises, inadequate experimentation, and confusion in the identity of samples with different dopant concentrations.
Physical Review B
Heist, Richard H.; Chilver, Charles R.; and Fong, Francis K., "Canonical Distribution Law and KCl: Sm2+ Fluorescence: The C2v Paradox" (1972). Engineering Faculty Publications. 165.
Heist, R. H., Chilver, C. R., & Fong, F. K. (1972). Canonical Distribution Law and KCl: Sm2+ Fluorescence: The C2v Paradox. Physical Review B, 5(11), 4237. doi:10.1103/PhysRevB.5.4237.