skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Direct Observations of Rapid Diffusion of Cu in Au Thin Films using In-Situ X-ray Diffraction

Abstract

In-situ x-ray diffraction was performed while annealing thin-film Au/Cu binary diffusion couples to directly observe diffusion at elevated temperatures. The temperature dependence of the interdiffusion coefficient was determined from isothermal measurements at 700 C, 800 C, and 900 C, where Cu and Au form a disordered continuous face centered cubic solid solution. Large differences in the lattice parameters of Au and Cu allowed the initial diffraction peaks to be easily identified, and later tracked as they merged into one diffraction peak with increased diffusion time. Initial diffusion kinetics were studied by measuring the time required for the Cu to diffuse through the Au thin film of known thickness. The activation energy for interdiffusion was measured to be 65.4 kJ/mole during this initial stage, which is approximately 0.4x that for bulk diffusion and 0.8x that for grain boundary diffusion. The low activation energy is attributed to the high density of columnar grain boundaries combined with other defects in the sputter deposited thin film coatings. As interdiffusion continues, the two layers homogenize with an activation energy of 111 kJ/mole during the latter stages of diffusion. This higher activation energy falls between the reported values for grain boundary and bulk diffusion, and maymore » be related to grain growth occurring at these temperatures which accounts for the decreasing importance of grain boundaries on diffusion.« less

Authors:
; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
898025
Report Number(s):
UCRL-JRNL-217421
TRN: US200706%%201
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Journal Article
Journal Name:
Journal of Vacuum Science and Technology - A, vol. 24(4), N/A, July 1, 2006, pp. 978-987
Additional Journal Information:
Journal Name: Journal of Vacuum Science and Technology - A, vol. 24(4), N/A, July 1, 2006, pp. 978-987
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; ANNEALING; COATINGS; DEFECTS; DIFFRACTION; DIFFUSION; FCC LATTICES; GRAIN BOUNDARIES; GRAIN GROWTH; KINETICS; LATTICE PARAMETERS; SOLID SOLUTIONS; TEMPERATURE DEPENDENCE; THICKNESS; THIN FILMS; X-RAY DIFFRACTION

Citation Formats

Elmer, J W, Palmer, T A, and Specht, E D. Direct Observations of Rapid Diffusion of Cu in Au Thin Films using In-Situ X-ray Diffraction. United States: N. p., 2005. Web.
Elmer, J W, Palmer, T A, & Specht, E D. Direct Observations of Rapid Diffusion of Cu in Au Thin Films using In-Situ X-ray Diffraction. United States.
Elmer, J W, Palmer, T A, and Specht, E D. 2005. "Direct Observations of Rapid Diffusion of Cu in Au Thin Films using In-Situ X-ray Diffraction". United States. https://www.osti.gov/servlets/purl/898025.
@article{osti_898025,
title = {Direct Observations of Rapid Diffusion of Cu in Au Thin Films using In-Situ X-ray Diffraction},
author = {Elmer, J W and Palmer, T A and Specht, E D},
abstractNote = {In-situ x-ray diffraction was performed while annealing thin-film Au/Cu binary diffusion couples to directly observe diffusion at elevated temperatures. The temperature dependence of the interdiffusion coefficient was determined from isothermal measurements at 700 C, 800 C, and 900 C, where Cu and Au form a disordered continuous face centered cubic solid solution. Large differences in the lattice parameters of Au and Cu allowed the initial diffraction peaks to be easily identified, and later tracked as they merged into one diffraction peak with increased diffusion time. Initial diffusion kinetics were studied by measuring the time required for the Cu to diffuse through the Au thin film of known thickness. The activation energy for interdiffusion was measured to be 65.4 kJ/mole during this initial stage, which is approximately 0.4x that for bulk diffusion and 0.8x that for grain boundary diffusion. The low activation energy is attributed to the high density of columnar grain boundaries combined with other defects in the sputter deposited thin film coatings. As interdiffusion continues, the two layers homogenize with an activation energy of 111 kJ/mole during the latter stages of diffusion. This higher activation energy falls between the reported values for grain boundary and bulk diffusion, and may be related to grain growth occurring at these temperatures which accounts for the decreasing importance of grain boundaries on diffusion.},
doi = {},
url = {https://www.osti.gov/biblio/898025}, journal = {Journal of Vacuum Science and Technology - A, vol. 24(4), N/A, July 1, 2006, pp. 978-987},
number = ,
volume = ,
place = {United States},
year = {Mon Nov 28 00:00:00 EST 2005},
month = {Mon Nov 28 00:00:00 EST 2005}
}