STRUCTURE AND LATTICE-DYNAMICS OF TITANIUM HYDRIDES DUE TO THERMOBARIC TREATMENT

An in situ X-ray diffraction study of the high-pressure zeta-phase evi denced a fct Ti sublattice. In the fco chi-phase quenched under pressu re, H atoms are displaced to octahedral sites, and the energy of H opt ic peak (at similar to 75 meV) is half that in other Ti-H phases where H occupy tetrahedral sites. Phase transformations on heating of chi-T iH(D)(similar to 0.75) were studied by neutron diffraction, small angl e and inelastic neutron scattering (INS). Bound multiphonons were obse rved in the INS spectra of ordered gamma-TiH(D).