A study of the optical and structural properties of the Na-Nd. beta. double prime -aluminas

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:7202541

Queenan, R L

The entire Na content of the fast ionic conductor Na {beta}{double prime}-alumina can be replaced by a variety of divalent and trivalent ions. The ion-exchange reactions with lanthanide salts provides a unique low temperature route for the preparation of a novel group of optical materials with possible applications as lasing devices. The synthesis conditions can be tailored to yield specific desirable optical properties by varying the kind of ion, and its concentration. One of the goals of this thesis work was to determine the effect of composition on the structural and optical properties of the Na-Nd{beta}{double prime}-aluminas. The optical and structural investigations revealed that composition and thermal treatment had a significant effect upon the optical and structural properties. The site preference of the Nd ion, and therefore the optical properties, varied with Nd concentration and thermal history, and upon slow-cooling, three-dimensional long-range ordered structures were formed throughout the binary system down to 20% of the Na replaced by Nd. Although the structural transitions were initially reversible, the ordered structure which formed as a result of long-term annealing treatments at 800C was very stable, and the disordered structure could no longer be quenched to room temperature. Possible models for the ordered structures were developed, and these gave good agreement with the structural and optical properties.

• Research Organization: Pennsylvania Univ., Philadelphia, PA (United States)
• OSTI ID: 7202541
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
ABSORPTION SPECTROSCOPY
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ANNEALING
CHALCOGENIDES
CHEMICAL PREPARATION
COHERENT SCATTERING
CRYSTAL STRUCTURE
DATA
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON DIFFRACTION
EXPERIMENTAL DATA
HEAT TREATMENTS
INFORMATION
IONIC CONDUCTIVITY
MICROSTRUCTURE
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
NUMERICAL DATA
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SCATTERING
SODIUM COMPOUNDS
SPECTROSCOPY
STOICHIOMETRY
SYNTHESIS
THERMAL ANALYSIS
X-RAY DIFFRACTION