Accession Number : AD0668446

Title :   OPTICAL SPECTRUM OF CR(3+) IONS IN SPINELS,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Kisliuk,P. P. ; Wood,D. L. ; MacFarlane,R. M. ; Imbusch,G. F. ; Larkin,D. M.

Report Date : MAR 1968

Pagination or Media Count : 35

Abstract : The optical absorption and fluorescence spectra of two spinels, ZnAl2O4:Cr(3+) and MgAl2O4:Cr(3+), were measured at temperatures between 4.2K and room temperature, and the data are fitted to a crystal field theory that includes spin-orbit coupling and the trigonal field of the D3 site. The parameters for a best fit for both crystals are: Delta = 18,250/cm, zeta = 250/cm, v = -200/cm, v' = -1700/cm, and k = 0.7. The (2)E and (4)A2 splittings, observed directly in the ZnAl2O4:Cr(3+) spectrum, are satisfactorily accounted for by the theory. The intensity of the R-lines is shown to be due to magnetic dipole transitions, and fluorescence lifetimes agree well with calculated values. Vibrational sidebands and pair lines observed in fluorescence are identified. (Author)

Descriptors :   (*CRYSTAL DEFECTS, SPECTROSCOPY), (*CHROMIUM, SPECTROSCOPY), SPINEL, IMPURITIES, ABSORPTION SPECTRA, FLUORESCENCE, FIELD THEORY, ATOMIC ORBITALS, EXCITATION, ULTRAVIOLET SPECTRA, VISIBLE SPECTRA

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE