PREPARATION AND PROPERTIES OF SCANDIUM DIHYDRIDE
Scandium dihydride was prepared and studied. Scandium was outgassed at 800 deg C in a silica tube. The tube was cooled to room temperature and connected to a series of calibrated volumes containing purified hydrogen at slightly below atmospheric pressure. Pressures were indicated on a manometer read by a cathetometer to the nearest 0.05 mm Hg. The metal was heated slowly until reaction was indicated by a drop in the manometer reading. At 450 deg C reaction was observed, and the experiment was held at 450 deg C for 16 hr. The metal was cooled slowly to room temperature to promote any additional metal- hydrogen reaction; none was observed. At this point, sufficient hydrogen had reacted to correspond to ScH/sub 2.o//sub 27/. The possibility was considered that a ScH/sub 3/, similar to YH/sub 3/, might be formed at lower temperatures. Two repetitions of the process yielded very little additional reaction. It is possible that ScH/sub 3/ is formed at higher hydrogen pressures. Vapor pressure data and x-ray powder-diffraction data are tabulated. The lattice constant and its standard deviation were determined by the method of Vogel and Kempter, a/sub o/ = 4.78309 plus or minus 0.00047 A at 25 plus or minus C. Correcting for refraction this becomes a/sub 0/ = 4.78315 A. For 4(ScH/sub 2/) per unit cell, the theoretical density is 2.851 g/cc, and the Sc-8H bond distance is 2.0712 A. ScH/sub 2/ may be useful as a high-temperature neutron moderator because it contains 7.31 x 10/sup 22/ hydrogen atoms/cc. (B.O.G.)
- Research Organization:
- Los Alamos Scientific Lab., N. Mex.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-15-009465
- OSTI ID:
- 4097719
- Journal Information:
- Journal of Chemical Physics (U.S.), Journal Name: Journal of Chemical Physics (U.S.) Vol. Vol: 33; ISSN JCPSA
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
BONDING
CHEMICAL REACTIONS
COOLING
DEGASSING
DENSITY
DIFFRACTION
EQUATIONS
ERRORS
HEATING
HIGH TEMPERATURE
HYDROGEN
IMPURITIES
LATTICES
LEVELS
MANOMETERS
MEASURED VALUES
METALS, CERAMICS, AND OTHER MATERIALS
MODERATORS
NEUTRONS
POWDERS
PREPARATION
PRESSURE
REFRACTION
SCANDIUM
SCANDIUM HYDRIDES
SILICON OXIDES
STANDARDS
TABLES
TEMPERATURE
TESTING
THICKNESS
TUBES
VAPORS
VOLUME
X RADIATION
YTTRIUM HYDRIDES