Efficient atomic-scale kinetics through a complex heterophase interface.
Atomic-scale imaging and first-principles modeling are applied to the heterophase interface between the Al-Cu solid solution (αCu) and θ' (Al2Cu) phases. Contrary to recent studies, our observations reveal a diffuse interface of complex but well-defined structure that enables the progression from αCu to θ' over a distance of ≈1  nm. We demonstrate that, surprisingly, the observed interfacial structure is not preferred on energetic grounds. Rather, the excess in interfacial energy is compensated by efficient atomic-scale kinetics of the αCu→θ' phase transformation.
Monash Centre for Electron Microscopy, Monash University, Victoria 3800, Australia. laure.bourgeois@monash.edu
Laure
L
Bourgeois
Nikhil V
NV
Medhekar
Andrew E
AE
Smith
Matthew
M
Weyland
Jian-Feng
JF
Nie
Christian
C
Dwyer