Production of crystalline refractory metal oxides containing colloidal metal precipitates and useful as solar-effective absorbers

Patent · Tue Mar 15 00:00:00 EST 1983

OSTI ID:6321503

Chen, Y; Narayan, J

This invention is a new process for producing refractory crystalline oxides having improved or unusual properties. The process comprises the steps of forming a doped-metal crystal of the oxide; exposing the doped crystal in a bomb to a reducing atmosphere at superatmospheric pressure and a temperature effecting precipitation of the dopant metal in the crystal lattice of the oxide but insufficient to effect net diffusion of the metal out of the lattice; and then cooling the crystal. Preferably, the cooling step is effected by quenching. The process forms colloidal precipitates of the metal in the oxide lattice. The process may be used, for example, to produce thermally stable black mgo crystalline bodies containing magnetic colloidal precipitates consisting of about 99% ni. The nicontaining bodies are solar-selective absorbers, having a roomtemperature absorptivity of about 0.96 over virtually all of the solar-energy spectrum and exhibiting an absorption edge in the region of 2 mu m. The process parameters can be varied to control the average size of the precipitates. The process can produce a black mgo crystalline body containing colloidal ni precipitates, some of which have the face-centered-cubic structure and others of which have the body-centered cubic structure. The products of the process are metal-precipitatecontaining refractory crystalline oxides which have improved or unique optical, mechanical, magnetic, and/or electronic properties.

• Assignee: Dept. of Energy
• Patent Number(s): US 4376755
• OSTI ID: 6321503
• Resource Relation: Patent File Date: Filed date 29 Jan 1982; Other Information: PAT-APPL-344085
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
MAGNESIUM OXIDES
CRYSTAL DOPING
SOLAR ABSORBERS
PRODUCTION
ALUMINIUM OXIDES
COLLOIDS
DISPERSIONS
NICKEL
REFRACTORY METALS
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
ELEMENTS
EQUIPMENT
MAGNESIUM COMPOUNDS
METALS
OXIDES
OXYGEN COMPOUNDS
SOLAR EQUIPMENT
TRANSITION ELEMENTS
141000* - Solar Collectors & Concentrators
360201 - Ceramics
Cermets
& Refractories- Preparation & Fabrication
360203 - Ceramics
Cermets
& Refractories- Mechanical Properties