Journal article
Stochastic Vacancy Motion in B2 Intermetallics Detected by PAC
MRS proceedings, Vol.527
1998
Handle:
https://hdl.handle.net/2376/121793
Abstract
Using perturbed angular correlation of gamma rays (PAC), nuclear relaxation has been detected at high temperature in highly ordered B2 intermetallics that is attributed to stochastic motion of vacancies near 111In/Cd probe atoms. The relaxation is of quadrupole interaction signals due to transition-metal vacancies in the first atomic shells of the probes. Possible relaxation mechanisms are reorientation of the vacancy with respect to the probe, detrapping of the vacancy, or trapping of a second vacancy. The relaxation reaches values of 10 MHz at temperatures of 1500K, 1200 K and 1170 K, respectively, for NiAI, FeAl and PdIn. For NiAl and FeAI, the onset of relaxation is abrupt, suggesting an activation enthalpy for the associated vacancy motion of several electron-volts. For PdIn, the relaxation has an activation enthalpy of 1.00(19) eV, a value significantly lower than might be expected naively on the basis of diffusion data. This difference gives insight into vacancy motion and diffusion mechanisms in PdIn.
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Details
- Title
- Stochastic Vacancy Motion in B2 Intermetallics Detected by PAC
- Creators
- Bin Bai - Washington State UniversityGary S Collins - Washington State UniversityHarmen Thys Nieuwenhuis - Washington State UniversityMingzhong Wei - Washington State UniversityWilliam E Evenson - Brigham Young University
- Contributors
- C.R.A Catlow (Editor)N.E.B Cowern (Editor)D Farkas (Editor)Y Mishin (Editor)G Vogl (Editor)
- Publication Details
- MRS proceedings, Vol.527
- Publisher
- Cambridge University Press
- Number of pages
- 6
- Identifiers
- 99900646681401842
- Language
- English
- Resource Type
- Journal article