Universality of Domain Growth in Antiferromagnets with Spin-Exchange Kinetics

Abstract

We study phase ordering kinetics in symmetric and asymmetric binary mixtures, undergoing an order-disorder transition below the critical temperature. Microscopically, we model the kinetics via antiferromagnetic Ising model with Kawasaki spin-exchange kinetics. This conserves the composition while the order-parameter (staggered magnetization) is not conserved. The order-parameter correlation function and structure factor show dynamical scaling, and the scaling functions are independent of the mixture composition. The average domain size shows a power-law growth: $L_{\sigma }(t)\sim t^{\alpha }$. The asymptotic growth regime has $\alpha =1/2$, though there can be prolonged transients with $\alpha <1/2$ for asymmetric mixtures. Our unambiguous observation of the asymptotic universal regime is facilitated by using an accelerated Monte Carlo technique. We also obtain the coarse-grained free energy from the Hamiltonian, as a function of two order-parameters. The evolution of these order-parameters is modeled by using \textit{Model C} kinetics. Similar to the microscopic dynamics, the average domain size of the nonconserved order-parameter (staggered magnetization) field exhibits a power-law growth: $L_m(t)\sim t^{1/2}$ at later times, irrespective of the mean value of the conserved order-parameter (composition) field.

arXiv comment21 Pages, 7 Figures, Accepted in EPJE

References in corpus (9)

• Theory of Phase Ordering Kinetics
• Domain Growth in Ising Systems with Quenched Disorder
• Domain Growth in Random Magnets
• Scaling Behavior of Response Functions in the Coarsening Dynamics of Disordered Ferromagnets
• Scaling in the Aging Dynamics of the Site-diluted Ising Model
• Ordering kinetics in an fcc A_3B binary alloy model: Monte Carlo studies
• Monte Carlo study of the growth of $L{1}_2$ ordered domains in fcc $A_{3}B$ binary alloys
• Kinetics of Joint Ordering and Decomposition in Binary Alloys
• Late stages of coarsening in model C

Cited by in corpus (2)

• Cell dynamics simulations of coupled charge and magnetic phase transformation in correlated oxides
• Phase Ordering Kinetics of the Asymmetric Coulomb Glass Model