Pokrovsky-Talapov critical behavior and rough-to-rough ridges of the sigma3 coincidence tilt boundary in Mo.
The as-grown shape of the cylindric tilt grain boundary (GB) in Mo bicrystals grown by the floating zone method has been studied with the electron backscattering diffraction method. The seed crystals were misoriented such that the coincidence site lattice (CSL) with lowest possible inverse density of coincidence sites, a Sigma=3 was grown. The flat (100)(Sigma3CSL) facets were observed forming smooth edges (no slope discontinuity) with rounded rough GB portions. Rough GBs curve away from the plane of the (100)(Sigma3CSL) facet as x(beta) with beta=1.69+/-0.07 on one side and beta=1.72+/-0.07 on the other side. Therefore, GB roughening belongs to the Pokrovsky-Talapov universality class. Slope discontinuities between two rounded rough GB portions were also observed. This is the first experimental observation of such first-order rough-to-rough ridges predicted by the Davidson-den-Nijs model.
Straumal
Boris B
BB
Institute of Solid State Physics, Russian Academy of Sciences, 142432 Chernogolovka, Moscow district, Russia.
Semenov
Valery N
VN
Kogtenkova
Olga A
OA
Watanabe
Tadao
T