Abstract
Domains in ferroelectric films are usually smooth, stripelike, very thin compared with magnetic ones, and satisfy the Landau-Lifshitz-Kittel scaling law (width proportional to square root of film thickness). However, the ferroelectric domains in very thin films of multiferroic have irregular domain walls characterized by a roughness exponent 0.5–0.6 and in-plane fractal Hausdorff dimension , and the domain size scales with an exponent rather than . The domains are significantly larger than those of other ferroelectrics of the same thickness, and closer in size to those of magnetic materials, which is consistent with a strong magnetoelectric coupling at the walls. A general model is proposed for ferroelectrics, ferroelastics or ferromagnetic domains which relates the fractal dimension of the walls to domain size scaling.
- Received 27 July 2007
DOI:https://doi.org/10.1103/PhysRevLett.100.027602
©2008 American Physical Society