Accession Number : AD0248962

Title :   PROTON MAGNETIC RESONANCE STUDIES OF STRUCTURE, DIFFUSION AND RESONANCE SHIFTS IN TITANIUM HYDRIDE

Corporate Author : ILLINOIS UNIV AT URBANA WILLIAM A NOYES LAB

Personal Author(s) : STALINSKI, B. ; COOGAN, C.K. ; GUTOWSKY, H.S.

Report Date : 06 OCT 1961

Pagination or Media Count : 1

Abstract : Measurements of the proton magnetic resonance at about 26.9 Mc/sec in titanium hydride samples, ranging in composition TiH1.61 to TiH1.97, have been made in the temperature range from -196 to about 200C. The second moment of the proton resonance at the lower temperatures shows that the hydrogen atoms are randomly distributed among (over) the lattice sites which are located tetrahedrally with respect to the titanium atoms. Self-diffusion of the hydrogen atoms narrows the proton resonance above room temperature. The temperature dependence of the correlation frequency for the proton motions, leads to diffusional activation energies which increase with hydrogen content from 9.4 kcal/g atom for TiH1.607 to 10.2 for TiH1.923. The diffusion rate is directly proportional to the number of unfilled tetrahedral holes in the metallic lattice, which indicates that the self-diffusion takes place via a vacancy mechanism. Proton resonance shifts to higher applied magnetic fields were observed. The were found to increase from 0.01% for TiH1.607 to about 0.032% for TiH1.969. The results suggest that the hydrogen is held in the lattice by a combination of covalent and ionic bonding, the latter involving a net positive charge on the hydrogen. (Author)

Descriptors :   *CRYSTAL LATTICES, *HYDRIDES, *NUCLEAR MAGNETIC RESONANCE, *TITANIUM COMPOUNDS, DIFFUSION, ELECTRONS, HYDROGEN, MAGNETIC FIELDS, PROTONS.

Distribution Statement : APPROVED FOR PUBLIC RELEASE