On the structural and luminescent properties of the M'LnTaO/sub 4/ rare earth tantalates

Journal Article · Thu Dec 01 00:00:00 EST 1983 · J. Electrochem. Soc.; (United States)

DOI:https://doi.org/10.1149/1.2119609· OSTI ID:6406869

Brixner, L H; Chen, H -Y

The structure of M YTaO/sub 4/ has been redetermined and was refined to an R value of 0.034. M'YTaO/sub 4/ crystallizes in P2/a symmetry with a = 5.298(1),b = 5.451(1),c = 5.111(1)A,..beta.. = 96.45 deg. At temperatures > 1450/sup 0/C,M'YTaO/sub 4/ will convert by way of a reconstructive transformation into the I4/sub 1//a symmetry of scheelite, and, upon cooling, a second-order ferroelastic transition (4/mF2/m) to M (fergusonite) YTaO/sub 4/ occurs. There are significant structural differences between M and M'YTaO/sub 4/ which are discussed. M'LnTaO/sub 4/ compounds exist from Ln = Sm to Lu. As a host for luminescent ions, M'YTaO/sub 4/ is superior to the M modification, as well as all other compounds in the Y/sub 2/O/sub 2/Ta/sub 2/O/sub 5/ phase diagram.

• Research Organization: E.I. du Pont de Nemours and Company, Central Research and Development Department, Experimental Station, Wilmington, Delaware
• OSTI ID: 6406869
• Journal Information: J. Electrochem. Soc.; (United States), Vol. 130:12
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
RARE EARTH COMPOUNDS
CRYSTAL STRUCTURE
LUMINESCENCE
PHASE STUDIES
TANTALATES
YTTRIUM COMPOUNDS
STRUCTURAL CHEMICAL ANALYSIS
COOLING
CRYSTAL-PHASE TRANSFORMATIONS
CRYSTALLIZATION
CRYSTALLOGRAPHY
PHASE DIAGRAMS
TEMPERATURE EFFECTS
VERY HIGH TEMPERATURE
DIAGRAMS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
REFRACTORY METAL COMPOUNDS
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360602* - Other Materials- Structure & Phase Studies