Internal friction of palladium containing hydrogen

Arons, R. R.; Bouman, J.; Wijzenbeek, M.; Klaase, P. T. A.; Tuyn, C.; Leferink, G.; Vries, G. de

doi:10.1016/0001-6160(67)90163-0

Cited by 50 publications

(3 citation statements)

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“…As was shown in chapter 3, there is a difference of for the activation energies, together with a ratio of the relaxation times between the hydrogenated and the deuterated specimens. Similar effects have been reported in the literature for the systems Pd-H, D [14], Fe-H, D [25], Nb-H, D [26]. They have also been observed and treated in detail in investigations of magnetoelastic relaxation by means of the magnetic aftereffect of hydrogen in ferromagnets (for a review, see e.g.…”

Section: Discussion -41 Relaxation Mechanism Forsupporting

confidence: 81%

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Hydrogen relaxation in lutetium

1983

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The internal friction and the dynamic modulus have been measured between 4.2 and 470 K in the system α-LuH(D)x, with x = 0 to 0.2. In well annealed specimens, an (H)-peak is observed at 215-225 K, which has a linearly x-dependent amplitude and exhibits an isotope effect on its activation energy and relaxation time. It is attributed to a Snoek-like relaxation of H-H pairs reorienting in the Lu-lattice. The isotope effect is interpreted in a model of tunnelling from different excited levels for LuHx and LuDx. Deformation introduces a (d-H)-peak at 250-260 K in H(D)-containing samples only, also exhibiting an isotope effect; it is attributed to a Snoek-Köster type relaxation of H(D) trapped on dislocations. Two (d1,2)-peaks at 160 and 215 K, which occur in the pure metal only, and a (d)-peak centred near 350 K in all deformed specimens are ascribed to geometrical kink migration and to double-kink generation on a screw dislocation network, respectively

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Section: Discussion -41 Relaxation Mechanism Forsupporting

confidence: 81%

“…Thus, internal-friction peaks in f.c.c. Pd(H, D)x had been attributed either to hydrogen pairing [14] or to a Zener-type rearrangement of H-interstitials and vacant interstitial sites [ 15], while a peak in H-charged austenitic stainless steel was ascribed to a hydrogen-substitutional solute atom pair [16]. The investigations of h.c.p.…”

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confidence: 99%

Hydrogen relaxation in lutetium

1983

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“…In the Zener effect the site symmetry is such that anelastic relaxation is not expected for an isolated hydrogen; however, hydrogen-hydrogen interactions lower the site symmetry and lead to anelastic relaxation. This is the situation for the octahedral (O) site in elemental fcc metals [36][37][38][39][40][41] and the T site in elemental hexagonal metals [42][43][44][45][46]. Depending as it does on H-H interactions, the magnitude of the Zener effect [47,48] depends on the hydrogen concentration as x 2 (1 − x 2 ) if the occupancy of the sites is not far from random.…”

Section: Introductionmentioning

confidence: 99%

Ultrasonic attenuation and dispersion due to hydrogen motion in the C15 Laves-phase compound TaV₂H_x

Foster

Hightower

Leisure

et al. 2001

J. Phys.: Condens. Matter

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Hydrogen in the C15 Laves-phase material TaV2Hx has been studied by means of resonant ultrasound spectroscopy over the temperature range of 15-345 K for a series of hydrogen concentrations (x = 0.00-0.53). Ultrasonic loss peaks and frequency shifts (dispersion) associated with the hydrogen motion were observed, yielding parameters for the hydrogen motion. Hydrogen in these materials is known to occupy the tetrahedral g sites which form a series of interlinked hexagons. The ultrasonic results were associated with H hopping between g-site hexagons. The relaxation rates for x⩽0.18 were best described as a sum of two Arrhenius processes. For x = 0.34 and 0.53 only a single Arrhenius process was needed to fit the results, although the presence of a second Arrhenius mechanism could not be over-ruled. A single relaxation rate was sufficient to fit the data; a distribution of rates was not required. The magnitudes of the attenuation and dispersion depended linearly on the hydrogen concentration implying that it is the relaxation of isolated H atoms (the Snoek effect) that is responsible for the mechanical damping. The faster local motion of H reported from nuclear magnetic resonance measurements for motion within g-site hexagons was not observed in the present study. This suggests that the H hopping rate for the local motion remains above the ultrasonic frequencies over the temperature range of study, or perhaps that too few H atoms participate in the local motion.

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