Interface roughness influence on exchange bias effect in La_2/3Ca_1/3MnO₃/La_1/3Ca_2/3MnO₃ bilayers

A Monte Carlo simulation study of La_2/3Ca_1/3MnO₃/La_1/3Ca_2/3MnO₃ bilayers exchange bias (EB) properties by using a classical Heisenberg model and Monte Carlo method with Metropolis algorithm is addressed. Samples were built atom-by-atom in order to resemble the real roughness. In this model, several contributions included nearest neighbors exchange interactions; two different interface couplings, magnetocrystalline anisotropy and Zeeman term, were considered. Here, an influence of the relaxation steps on the interface roughness is present. Our study focuses on the influence of interface roughness on hysteresis loops, particularly EB field (H _ex) and coercive force (H _c). Results reveal that H _ex and H _c decrease as the interface roughness increases.