Nuclear Magnetic Resonance of Ti in Ti–H Systems

The nuclear magnetic resonance spectrum of 47,49Ti in powder samples of metallic titanium hydride TiHx has been studied over the range of hydrogen concentrations corresponding to 1.7 ≤ x ≤ 2.0. For TiH2 the Knight shift is found to be +0.26 ± 0.04%, and there is no change in the Knight shift as a function of hydrogen concentration over the range studied. The titanium resonance in all samples was quite broad, 20 Oe, so that the lines from the two isotopes were not resolved. As a function of hydrogen concentration, the line shape was found to remain constant, but a rapid decrease of line intensity was noted. In order to investigate the possibility of magnetic ordering suggested by earlier studies of the magnetic susceptibility of TiH2, studies of the magnetic-field dependence and temperature dependence of the resonance were also performed. No dependence of Knight shift or line shape on magnetic field was observed over the range 9.0–15.0 kOe. No changes in Knight shift or line shape were observed in the temperature region 170°–525°K, thoroughly encompassing the region of the magnetic susceptibility maximum at approximately 300°K. These results strongly suggest that the cause of the maximum in the magnetic susceptibility is not magnetic ordering. Results on hydrogen and deuterium resonances in these samples are also reported.