Defect solid state chemistry of lanthanum magnesium hexaaluminate

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:567898

Park, J G; Cormack, A N ^[1]

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1. Alfred Univ., NY (United States)

Lanthanum magnesium hexa-aluminate (LMA, ideally LaMgAl{sub 11}O{sub 19}), having a structure close to that of magnetoplumbite (MP, PbFe{sub 12}O{sub 19}) (space group P6{sub 3}/mmc), is currently of interest as a high efficiency host material for the active elements of solid-state lasers. The luminescent properties of substituted rare earth elements in LMA are affected by the interaction of some unknown point defects with the active elements, leading to unwanted optical absorption. It is obvious that, due to the complexity of the basic crystal structure of MP type compounds, detailed information about their point defect properties is not readily available from experiment. In this paper, as part of our systematic studies on the structure, stoichiometry, and stability in hexa-aluminates, we investigate the defect energetics and nonstoichiometry in LMA, using theoretical, computer-based atomistic simulation techniques. The site preference of Mg in LMA and the effect of Mg distribution on the MP structure are also discussed.

• DOE Contract Number: FG02-91ER45451
• OSTI ID: 567898
• Report Number(s): CONF-9505249--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINATES
ALUMINIUM OXIDES
CALCULATION METHODS
CRYSTAL STRUCTURE
LANTHANUM OXIDES
LUMINESCENCE
MAGNESIUM OXIDES
POINT DEFECTS
SOLID STATE LASERS
STOICHIOMETRY