X-RAY DIFFRACTION STUDIES OF THE HYDRIDES OF ZIRCONIUM, TITANIUM, AND HAFNIUM AT ELEVATED TEMPERATURES. Period Covered: January 1957 to January 1958

Technical Report · Tue Apr 01 04:00:00 EST 1958

DOI:https://doi.org/10.2172/4340543· OSTI ID:4340543

Goon, E J; Malgiolio, J

X-ray-diffraction data have been obtained for the hydrides of titanium, zirconium, and hafnium from room temperature to 650 deg C and at hydrogen gas pressures from 2 mm to 600 psi. No new hydride phases were observed. Evidence has been obtained in support of the work of Vaughan that the various phases previously reported for zirconium hydride are derived from the tetragonal phase with the axial ratio, c/a, less than one. When hydrogen is slowly removed from epsilon -- ZrH/sub 2/ (c/a < 1), the axial ratio increases to and may pass through unity. Hafnium hydride transforms from a tetragonal to the cubic phase in the same manner as does zirconium hydride. The lattice parameter of cubic hafnium hydride ranges from 4.722 to 4.719 A, and from 4.717 to 4.714 As the parameters are both temperature and pressure dependent. The only hydride phase observed for titanium hydride is the face-centered cubic phase. The anomalous variation of lattice parameter of titanium hydride with temperature at constant pressure may be attributed to a change of some of the hydrogen positions from the tetrahedral sites to the octahedral sites of a fluorite type lattice. (auth)

• Research Organization: Tufts Coll., Medford, Mass.
• NSA Number: NSA-12-009051
• OSTI ID: 4340543
• Report Number(s): NYO-7547
• Country of Publication: United States
• Language: English

Related Subjects

CHEMISTRY
DIFFRACTION
EQUATIONS
FLUORINE COMPOUNDS
FLUORITE
GASES
HAFNIUM HYDRIDES
HYDROGEN
LATTICES
PRESSURE
TEMPERATURE
TITANIUM HYDRIDES
X RADIATION
ZIRCONIUM HYDRIDES