Accession Number : ADA180746

Title :   Absorption Spectra and Energy Levels of Sm3+:Y3Al5O12.

Descriptive Note : Final rept. Jan 85-Aug 86,

Corporate Author : HARRY DIAMOND LABS ADELPHI MD

Personal Author(s) : Bruber,John B. ; Hills,Marian E. ; Nadler,Melvin P. ; Kokta,Milan R. ; Morrison,Clyde A.

Report Date : APR 1987

Pagination or Media Count : 29

Abstract : Absorption spectra between O.2 and 6.7 micrometer are reported for trivalent samarium in single-crystal yttrium aluminum garnet, Y3Al5O12, at liquid nitrogen, and room temperatures. Energy levels (4f5SLj) associated with sextet, quartet, and doublet states of Sm3+2 are established from data between 1,500 and 46,000 cm. Most samarium ions occupy yttrium ion sites, which have D2 point-group symmetry in the lattice. A free-ion wavefunction calculation predicts the assignment of 35 isolated SLj manifolds with an rms deviation of 32 cm between calculated and observed centers of gravity. A Hamiltonian consisting of coulombic, spin-orbit, and crystalline electric field (D2 symmetry) terms is diagonalized for the two lowest sextet states 6Hj and 6Fj. The calculated Stark levels based on a single set of Kkm crystal field parameters are compared to the observed levels (54), yielding an rms deviation of 4.9 cm. Keywords: Spectra, rare earth, samarium, yttrium, alumimum.

Descriptors :   *ABSORPTION SPECTRA, *CRYSTALS, *ENERGY LEVELS, *RARE EARTH ELEMENTS, *SAMARIUM, *YTTRIUM, LIQUID NITROGEN, ROOM TEMPERATURE, IONS, VALENCE, SITES, GRAVITY, ELECTRIC FIELDS, HAMILTONIAN FUNCTIONS, STARK EFFECT

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE