Short range order structural investigations of several amorphous lanthanide hydrous oxides

Miscellaneous · Wed Jan 01 00:00:00 EST 1992

OSTI ID:7166085

Leschnitzer, D H

Seven amorphous lanthanide oxides, europium, gadolinium, terbium, dysprosium, thulium, ytterbium, and lutetium, were synthesized in order to study their short range order. Synthesis procedures and peripheral investigations including X-ray powder diffraction, TGA, DSC, IR, and SEM are discussed in detail. The theory behind the X-ray scattering techniques and a detailed discussion of data treatment and normalization are also presented. A modified Siemens-K805 type F horizontal goniometer diffractometer with a custom monochromator and Kevex Si(Li) center-of-gravity solid state detector was employed for the data collection and is described in detail. The lanthanide systems Eu through Yb were nine-coordinated and the lutetium sample had a coordination number between 6 and 7 (6.4). Calculated Ln-O distances ranged from 2.46 down to 2.34 [angstrom]. Also reported are Ln-Ln and O-O distances and O-Ln-O angles. Scattering profiles, interference functions, radial distribution functions, and pair functions are displayed for each of the studied compounds. In addition, structural modeling was performed to try to classify the coordination geometry. The systems Eu through Yb appear to closely match the tricapped trigonal prism geometry, D[sub 3h], of their corresponding trihydroxide counterparts. The lutetium sample appears to be a mixture of both six-coordinated octahedrally oriented metal centers and seven-coordinated monocapped trigonal prism oriented metal centers. The modeling techniques, as well as their pros and cons, are discussed.

• Research Organization: Baylor Univ., Waco, TX (United States)
• OSTI ID: 7166085
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
OXIDES
MOLECULAR STRUCTURE
RARE EARTH COMPOUNDS
BOND ANGLE
BOND LENGTHS
DYSPROSIUM OXIDES
EUROPIUM OXIDES
GADOLINIUM OXIDES
LUTETIUM OXIDES
TERBIUM OXIDES
THULIUM OXIDES
YTTERBIUM OXIDES
CHALCOGENIDES
DIMENSIONS
DYSPROSIUM COMPOUNDS
EUROPIUM COMPOUNDS
GADOLINIUM COMPOUNDS
LENGTH
LUTETIUM COMPOUNDS
OXYGEN COMPOUNDS
TERBIUM COMPOUNDS
THULIUM COMPOUNDS
YTTERBIUM COMPOUNDS
400201* - Chemical & Physicochemical Properties
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies