Nanoscale diffusion in Pt/56Fe/57Fe thin-film system
Low-temperature diffusion of Fe in Pt/56Fe/57Fe thin films (grown on MgO (100) substrate) was investigated between 703K and 813K using secondary neutral mass spectrometry. The activation energy of the effective interdiffusion coefficients, evaluated by the “centre-gradient” method, is 1.53±0.25eV re...
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Published in | Thin solid films Vol. 589; pp. 173 - 181 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
01.08.2015
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Subjects | |
Online Access | Get full text |
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Summary: | Low-temperature diffusion of Fe in Pt/56Fe/57Fe thin films (grown on MgO (100) substrate) was investigated between 703K and 813K using secondary neutral mass spectrometry. The activation energy of the effective interdiffusion coefficients, evaluated by the “centre-gradient” method, is 1.53±0.25eV reflecting a strong contribution from grain boundaries. This is also supported by the observed deep penetrations of Pt into the 56Fe layer, from which the grain boundary diffusion coefficients for Pt in Fe were also estimated and 1.45±0.25eV activation energy was obtained. A simple model, including the effect of grain boundaries to the overall intermixing at the original sharp interfaces in nanocrystalline films, is developed. This predicts that at short annealing times the grain boundary diffusion dominates, and bulk diffusion coefficients can be determined only in long time limit. At intermediate annealing times, when the grain boundaries are saturated but the bulk diffusion is still negligible, there are no changes in the composition profiles. This yields good qualitative agreement with the experimental data and offers explanation for the time and temperature dependence of the interdiffusion coefficients obtained in similar systems.
•Effective self-diffusion coefficients for Fe were determined in the range 703-813K•Time dependent effective diffusion coefficients found•A model with mixed diffusion paths was used to interpret the results |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0040-6090 1879-2731 |
DOI: | 10.1016/j.tsf.2015.04.069 |