The Effect of Defects on Magnetic Droplet Nucleation

Abstract

Defects and impurities strongly affect the timing and the character of the (re)ordering or disordering transitions of thermodynamic systems captured in metastable states. In this paper we analyze the case of two-dimensional magnetic systems. We adapt the classical JMAK theory to account for the effects of defects on the free energy barriers, the critical droplet area and the associated metastable time. The resulting predictions are successfully tested against the Monte-Carlo simulations performed by adopting Glauber dynamics, to obtain reliable time-dependent results during the out-of-equilibrium transformations. We also focus on finite-size effects, and study how the spinodal line (separating the singledroplet from the multi-droplet regime) depends on the system size, the defect fraction, and the external field.

29 pages, 10 figures

References in corpus (8)

• Multi-GPU Accelerated Multi-Spin Monte Carlo Simulations of the 2D Ising Model
• Lack of self-averaging of the specific heat in the three-dimensional random-field Ising model
• Zero and low temperature behavior of the two-dimensional $\pm J$ Ising spin glass
• Absence of replica symmetry breaking in the random field Ising model
• No spin glass phase in ferromagnetic random-field random-temperature scalar Ginzburg-Landau model
• Universality in disordered systems: The case of the three-dimensional random-bond Ising model
• Metastable behavior of the spin-s Ising and Blume-Capel ferromagnets: A Monte Carlo study
• Temperature-dependent criticality in random 2D Ising models

Cited by in corpus (3)

• Finite-temperature avalanches in 2D disordered Ising models
• Dynamic Phase Transition in 2D Ising Systems: Effect of Anisotropy and Defects
• Inter-Event Time Power Laws in Heterogeneous Systems