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The Anomalous Spectral Density Function for Diffusive Motion of Hydrogen in LaNi5H7*

Published online by Cambridge University Press:  15 February 2011

H. Chang
Affiliation:
Physics Department, University of Pittsburgh, Pittsburgh, PA 15260
I. J. Lowe
Affiliation:
Physics Department, University of Pittsburgh, Pittsburgh, PA 15260
R. J. Karlicek Jr.
Affiliation:
Chemistry Department, University of Pittsburgh, Pittsburgh, PA 15260
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Abstract

Measurements of T1 (Bo = 0.94T), and T1r as a function of temperature have been carried out on a LaNi5H7 sample at 4 different rotating magnetic field values. The T1 and T1r data are consistent with earlier data by Karlicek and Lowe [3,4], in which an asymmetry in the slopes of the log T1r vs. T−1 plot was found. The new data has been analyzed assuming a spectral density function J(ω,τc) of form J(ω, τc) = A(τc)B(Ω)F(ωτc), with τc = τc∞ exp(Ea/kT). This assumption leads to a spectral density function that fits all our data well, with Ea = 39 KJ/gm-Atom H, and J(ω)∼ Wω−1.35 in the high frequency limit. This Ea agrees well with the Ea obtained from diffusion constant measurements.

Type
Research Article
Copyright
Copyright © Materials Research Society 1981

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Footnotes

Now at Bell Telephone Laboratories, Murray Hill, N.J.

*

Supported by NSF Grant DMR 78–15441

References

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