Surface critical behavior of bcc binary alloys

Abstract

The surface critical behavior of bcc binary alloys undergoing a continuous B2-A2 order-disorder transition is investigated in the mean-field (MF) approximation. Our main aim is to provide clear evidence for the fact that surfaces which break the two-sublattice symmetry generically display the critical behavior of the NORMAL transition, whereas symmetry-preserving surfaces exhibit ORDINARY surface critical behavior. To this end we analyze the lattice MF equations for both types of surfaces in terms of nonlinear symplectic maps and derive a Ginzburg-Landau model for the symmetry-breaking (100) surface. The crucial feature of the continuum model is the emergence of an EFFECTIVE ORDERING (``staggered'') SURFACE FIELD, which depends on temperature and the other lattice model parameters, and which explains the appearance of NORMAL critical behavior for symmetry-breaking surfaces.

16 pages, REVTeX 3.0, 13 EPSF figures, submitted to Phys. Rev. B

Cited by in corpus (9)

• Massive Field-Theory Approach to Surface Critical Behavior in Three-Dimensional Systems
• Critical phenomena at perfect and non-perfect surfaces
• Surface scaling behavior of isotropic Heisenberg systems: Critical exponents, structure factor, and profiles
• Dynamic critical behavior of model A in films: Zero-mode boundary conditions and expansion near four dimensions
• Structure factor of thin films near continuous phase transitions
• Anomalies in the Multicritical Behavior of Staggered Magnetic and Direct Magnetic Susceptibilities of Iron Group Dihalides
• Boundary critical behaviour at $m$-axial Lifshitz points: the special transition for the case of a surface plane parallel to the modulation axes
• Surface induced disorder in body-centered cubic alloys
• Confinement Effects in Antiferromagnets