TY  - JOUR
AU  - Boussinot, G.
AU  - Brener, Efim
TI  - Interface kinetics in phase-field models: Isothermal transformations in binary alloys and step dynamics in molecular-beam epitaxy
JO  - Physical review / E
VL  - 88
IS  - 2
SN  - 1539-3755
CY  - College Park, Md.
PB  - APS
M1  - FZJ-2015-03759
SP  - 022406
PY  - 2013
AB  - We present a unified description of interface kinetic effects in phase-field models for isothermal transformations in binary alloys and steps dynamics in molecular-beam-epitaxy. The phase-field equations of motion incorporate a kinetic cross-coupling between the phase field and the concentration field. This cross-coupling generalizes the phenomenology of kinetic effects and was omitted until recently in classical phase-field models. We derive general expressions (independent of the details of the phase-field model) for the kinetic coefficients within the corresponding macroscopic approach using a physically motivated reduction procedure. The latter is equivalent to the so-called thin-interface limit but is technically simpler. It involves the calculation of the effective dissipation that can be ascribed to the interface in the phase-field model. We discuss in detail the possibility of a nonpositive definite matrix of kinetic coefficients, i.e., a negative effective interface dissipation, although being in the range of stability of the underlying phase-field model. Numerically we study the step-bunching instability in molecular-beam-epitaxy due to the Ehrlich-Schwoebel effect, present in our model due to the cross-coupling. Using the reduction procedure we compare the results of the phase-field simulations with the analytical predictions of the macroscopic approach.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000323576400009
DO  - DOI:10.1103/PhysRevE.88.022406
UR  - https://juser.fz-juelich.de/record/201464
ER  -