Triple junction transport and the impact of grain boundary width in nanocrystalline Cu.
Triple junctions (TJ), singular topological defects of the grain boundary (GB) structure, get a dominant role for grain growth and atomic transport in nanocrystalline matter. Here, we present detailed measurements by atom probe tomography, even of the temperature dependence of TJ transport of Ni in nanocrystalline Cu in the chemical regime of interdiffusion. An unexpected variation of the effective width of merging GBs with temperature is detected. It is demonstrated that proper measurement of TJ transport requires taking into account this remarkable effect. TJ diffusion is found to be a factor of about 200 faster than GB diffusion. Its activation energy amounts to only two-thirds of that of the GB.
Institut für Materialphysik, Westfälische Wilhelms Universität Münster, Wilhelm Klemm Straße 10, D-48149, Münster, Germany. m_chel01@uni-muenster.de
Mohammed Reda
MR
Chellali
Zoltan
Z
Balogh
Houari
H
Bouchikhaoui
Ralf
R
Schlesiger
Patrick
P
Stender
Lei
L
Zheng
Guido
G
Schmitz