Use of polarized optical absorption to obtain structural information for Na{sup +}/Nd{sup 3+} {beta}{double_prime}-alumina

Journal Article · Sun Dec 01 04:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.54.17476· OSTI ID:404049

Edvardsson, S ^[1]; Klintenberg, M; Thomas, J O ^[2]

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1. Department of Physics and Mathematics, Mid Sweden University, S-851 70 Sundsvall (Sweden)
2. Institute of Chemistry, Uppsala University, Box 531, S-751 21 Uppsala (Sweden)

Part of the optical absorption spectrum is calculated for the Nd{sup 3+}-doped Na{sup +} {beta}{double_prime}-alumina using a molecular-dynamics- (MD) based approach. The Judd/Ofelt (J/O) theory is modified (and several approximations removed) to treat polarized transition intensities for rare-earth ions in a solid host. Stark-level energies and eigenfunctions of the ground state ({sup 4}{ital I}{sub 9/2}) and excited multiplets ({sup 4}{ital F}{sub 3/2},{sup 2}{ital P}{sub 1/2}) are also calculated for the local environments involved. Energies and polarized transition intensities between individual Stark levels are thus calculated simultaneously for several hundreds of MD-generated environments; summation gives the total bandshape. A high proportion of Beevers-Ross-site occupation ({gt}50{percent}) is indicated for low Nd{sup 3+} concentrations in {beta}{double_prime}-alumina. The contrary is observed experimentally for high Nd{sup 3+} concentrations, i.e., then midoxygen site occupation dominates. It is demonstrated that ions in different local environments contribute differently to the absorption spectrum and, particularly, how the polarization of the various transitions changes for ions occupying different sites. Temperature dependence aspects are also considered. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 404049
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 24 Vol. 54; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTRA
ALUMINIUM OXIDES
CRYSTAL FIELD
ENERGY LEVELS
MOLECULAR DYNAMICS CALCULATIONS
NEODYMIUM IONS
OPTICAL PROPERTIES
POLARIZATION
SODIUM IONS
STARK EFFECT
TEMPERATURE DEPENDENCE