On the High-Frequency Limit of Lattice Vibrations in Zirconium Hydrides and Deuterides

On the Dynamics and Site Occupation of D Atoms in ? and ? Deuterides of Zr

“…These results are related to the investigation of the energy range higher than that characteristic of the host lattice vibrations. An accurate analysis of the latter at the transition from pure a-Zr to the hydride (deuteride) phases has been reported in a previous paper [9].…”

“…However, the main interest has been devoted so far to the high energy H(D) optical vibrations and only little effort has been made to study the acoustic range and the energy range just above the Debye limit of the lattice vibrations. Recent results obtained by INS [7,8] revealed that H behaviour in the Zr±H system is still far from a complete knowledge.…”

“…A complete study of the latter was reported in [9]. Evidence of increasing scatter- ing intensity was also revealed at flight times which are intermediate between those corresponding to the optical and acoustic regions (Fig.…”

High-Temperature Investigation of the Dynamics and Thermodynamics of ZrH-U System by Neutron Scattering

“…A more detailed description of sample preparation, experimental procedure and time-of-flight measured data is reported in [25]. Here we would like to point out only the effect of the highly absorption uranium addition (s a ¼ 7:57 barn, s s ¼ 8:908 barn) to the measured scattering spectrum: from the comparison between the neutron scattering spectra on ZrH 1:6 U 0:32 and ZrH 1:6 [26] measured at room temperature with the same incident neutron energy, it was concluded that the effect of the presence of uranium consists of a lower counting rate and does not influence the main features of the spectra revealing dynamic effects taking place in the investigated system.…”

“…A detailed microscopic investigation of the changes on the vibrational and thermodynamic properties according to different spatial distributions of Zr atoms in transition from pure metal to stoichiometric hydride or deuteride has been only recently performed [22]. Also, an accurate investigation of the evolution of microscopic properties in the range of high temperatures and the correlation with changes in macroscopic properties have not been completely performed by now.…”