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

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