Disordered dipolar solids: Anisotropic growth laws and their slowing-down

Abstract

We use Monte Carlo simulations to study the kinetics of domain growth in the d = 3 random-field Ising model with dipolar interactions (RFIM+DI). This system models a large class of magnetic and dielectric solids. Our main results are as follows: i) The domains are anisotropic and elongated along the Ising (z) axis. The system exhibits generalized dynamical scaling with two distinct length scales and , where . However, the scaling function is not robust with respect to the disorder Δ. ii) For a fixed value of Δ, the interfaces are fractal with distinct fractal dimensions in the xy-plane and the z-direction. iii) The domain growth laws are also anisotropic, and exhibit distinct power laws on the time-scales of our simulations: and . iv) The exponents and have a simple dependence on Δ. Our results are novel and provide a fresh outlook to interpret experiments in disordered dipolar solids.