Effects of temperature on domain-growth kinetics of fourfold-degenerate (2×1) ordering in Ising models

Abstract

Computer-simulation techniques are used to study the domain-growth kinetics of (2\ifmmode\times\else\texttimes\fi{}1) ordering in a two-dimensional Ising model with nonconserved order parameter and with variable ratio $\ensuremath{\alpha}$ of next-nearest- and nearest-neighbor interactions. At zero temperature, persistent growth characterized by the classical growth exponent $n\ensuremath{\simeq}\frac{1}{2}$ is found for $\ensuremath{\alpha}\ensuremath{\ge}1$, whereas the domain boundaries become pinned and the growth stops for $\ensuremath{\alpha}<1$. For finite temperatures and $\ensuremath{\alpha}\ensuremath{\ge}1$, the growth exponent is found to be temperature independent in a wide regime, and for $\ensuremath{\alpha}\ensuremath{\le}1$ the domain walls unpin and growth resumes.