Kinetics of Order-Disorder Transitions in Binary Mixtures: A Monte Carlo Study

27th IUPAP Conference on Computational Physics

物理学;计算机科学

Das, Prasenjit^1 ; Saha-Dasgupta, Tanusri^2 ; Puri, Sanjay^1

School of Physical Sciences, Jawaharlal Nehru University, New Delhi

110067, India^1

S. N. Bose National Centre for Basic Sciences, Kolkata

700098, India^2

关键词: Asymmetric mixtures;    Average domain size;    Critical temperatures;    Ferromagnetic Ising models;    Kawasaki spin-exchange kinetics;    Microscopic dynamics;    Mixture compositions;    Monte Carlo techniques;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/759/1/012010/pdf
DOI  :  10.1088/1742-6596/759/1/012010

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

We study ordering kinetics in symmetric and asymmetric binary mixtures, undergoing an order-disorder transition below the critical temperature. We model the microscopic dynamics via an anti-ferromagnetic Ising model with Kawasaki spin-exchange kinetics. This conserves the composition but the order parameter, (staggered magnetization) is not a conserved quantity. The order-parameter correlation function shows dynamical scaling, and the scaling function is independent of mixture composition. The average domain size exhibits power law growth: L(t) ∼ tα. The asymptotic growth regime has α = 1/2, though there can be prolonged transients with α