Monte Carlo approach for studying microphases applied to the axial next-nearest-neighbor Ising and the Ising-Coulomb models | |
Article | |
关键词: MEAN-FIELD-THEORY; SPATIALLY MODULATED PHASE; DIBLOCK COPOLYMER MELTS; HIGH-TEMPERATURE SERIES; TO-LAMELLAR TRANSITION; COIL BLOCK-COPOLYMERS; CRITICAL-BEHAVIOR; COMPETING INTERACTIONS; LIFSHITZ POINT; ANNNI MODEL; | |
DOI : 10.1103/PhysRevB.83.214303 | |
来源: SCIE |
【 摘 要 】
The equilibrium phase behavior of microphase-forming systems is notoriously difficult to obtain because of the extended metastability of their modulated phases. In this paper we present a systematic simulation methodology for studying layered microphases and apply the approach to two prototypical lattice-based systems: the three-dimensional axial next-nearest-neighbor Ising (ANNNI) and Ising-Coulomb (IC) models. The method involves thermodynamically integrating along a reversible path established between a reference system of free spins under an ordering field and the system of interest. The resulting free-energy calculations unambiguously locate the phase boundaries. Simple phases are not found to play a particularly significant role in the devil's flowers and interfacial roughening plays at most a small role in the ANNNI layered regime. With the help of generalized order parameters, the paramagnetic-modulated critical transition of the ANNNI model is also studied. We confirm the XY universality of the paramagnetic-modulated transition and its isotropic nature.
【 授权许可】
Free