Hydrogen, Deuterium and Tritium in Palladium: An Elastic Constants Study

Journal Article · Fri Jul 15 04:00:00 EDT 2005 · Fusion Science and Technology

OSTI ID:20854206

Bach, H T; Schwarz, R B; Tuggle, D G ^[1]

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1. Los Alamos National Laboratory (United States)

We have used resonant ultrasound spectroscopy to measure the three independent elastic constants of Pd-H, Pd-D, and Pd-T single crystal at 300K as a function of hydrogen, deuterium, and tritium concentration, respectively. The addition of interstitial H (D, or T) atoms, located at (0,1/2,0) in the fcc Pd lattice, affects all three elastic constants C', C{sub 44}, and B. In the mixed ({alpha}+{beta}) phase, and with increasing H isotope, the shear modulus C' shows an abnormal softening whereas C{sub 44} and B do not. This is explained in terms of Zener-type an elastic relaxations affecting the shape of the hydride phases in the coherent({alpha}+{beta}) two-phase mixture In the single {beta}-phase, C' shows a strong isotope dependence whereas C{sub 44} and B show none. This behavior is explained in terms of differences in the excitation of optical phonons. In Pd-T, {sup 3}He is produced by the radioactive decay of tritium. We have measured in situ the swelling and the change in the elastic constants in Pd-T as a function of aging time. Aging ({sup 3}He formation) affects all three elastic constants. These measurements are being used to understand the early stages of {sup 3}H-{sup 3}He cluster formation in aged Pd-T crystal.

• OSTI ID: 20854206
• Journal Information: Fusion Science and Technology, Journal Name: Fusion Science and Technology Journal Issue: 1 Vol. 48; ISSN 1536-1055
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AGING
DEUTERIUM
ELASTICITY
EXCITATION
FCC LATTICES
HELIUM 3
HYDRIDES
HYDROGEN
MIXTURES
MONOCRYSTALS
NUCLEAR DECAY
PALLADIUM
PHONONS
RELAXATION
SHEAR
SPECTROSCOPY
SWELLING
TRITIUM
ULTRASONIC WAVES