For example see: M. J. Weber and R. W. Bierig, Phys. Rev. 134A, 1492 (1964) and the references therein.
I. V. Stepanov and P. P. Feofilov, Dokl. Akad. Nauk. SSSR 1, 350 (1957).
N. Rabbiner, Phys. Rev. 130, 502 (1963).
T. F. Ewanizky, P. J. Caplan, and J. R. Pastore, J. Chem. Phys. 43, 4351 (1965).
K. Muto and K. Awazu, J. Phys. Chem. Solids 29, 1269 (1968).
K. W. H. Stevens, Proc. Phys. Soc. (London) A65, 209 (1952).
N. Rabbiner, J. Opt. Soc. Am. 57, 217, 1376 (1967); Ph.D. thesis, New York University (1967), available from University Microfilms, Ann Arbor, Michigan.
See M. T. Hutchings, Solid State Phys. 16, 227 (1964) and references therein.
The crystal-field parameters (A's) are related to the parametres of the crystal field (B's) by the equations: Bnm = ηnAnm〈rn〉 where ηn are the operator-equivalent factors.6
Recently, Muto and Awazu5 have investigated the CaF2: Sm3+ fluorescent spectra. The number of lines observed for the Type I spectra was less than the number we have reported,3 which may have been due to intensities too weak to disclose the weaker lines. The frequencies of the lines observed5 agreed well with those of the stronger lines we observed.3 Muto amd Awazu5 considered the possibility that this Type I, CaF2: Sm3+ spectra arises from transitions between the 4F5/2 and6H5/2, 6H7/2, 6H9/2 states of Sm3+. However, even assuming that the weaker lines which we reported3 and Muto and Awazu5 did not observe can be neglected, the remaining strong lines do not fit into an empirical-energy-level scheme for C3 symmetry between these states; i.e., some lines observed can not be included in such a scheme although the total number of such strong lines observed5 is less than that theoretically permissible. Thus, there apparently is not much support for a possible assumption of 4F5/2 as the fluorescent upper state for the Type I crystal.