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Kinetics of coupled ordering and segregation in antiphase domains
Author(s) -
Gumennyk K.,
Stefanovich L.,
Feldman E.
Publication year - 2009
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200844277
Subject(s) - alloy , relaxation (psychology) , statistical physics , lattice (music) , redistribution (election) , kinetics , order (exchange) , domain (mathematical analysis) , kinetic energy , binary number , diffusion , thermodynamics , range (aeronautics) , condensed matter physics , materials science , crystallography , chemistry , physics , mathematics , classical mechanics , mathematical analysis , psychology , social psychology , arithmetic , finance , politics , political science , acoustics , law , economics , composite material
We study a multi‐domain ordering kinetics in solid solutions under simultaneous diffusion of solute atoms. By the example of a binary bcc alloy a system of kinetic equations is derived, describing the coupled relaxation of occupancies of the two sublattices, building a bcc lattice, by A and B atomic species. Such an approach supplemented by the simplest mean‐field approximation proves sufficient to describe both the establishing of long‐range order and the segregation processes occurring in antiphase domains. An interaction and interrelation between evolution of the conserved and non‐conserved order parameter fields are elucidated. Asymptotical and numerical analysis of the obtained evolution equations reveals a multi‐stage scenario of the alloy relaxation: first comes the quick development of long‐range order which is then followed by the slow redistribution of local alloy concentration, so that the majority atoms segregate towards the region of an antiphase boundary. The alloy exhibits a distinct tendency to form a multi‐domain structure out of a solitary long‐range order parameter fluctuation of a certain sign. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)