BiFeO₃ is the archetypal room-temperature multiferroic and is almost always studied as a ferroelectric. By extending an in-house Fortran-based Effective Hamiltonian Monte Carlo model from 3D bulk to 2D thin-film geometries — and explicitly including surface effects as a function of thickness — we found that sufficiently thin BFO films exhibit antiferroelectric-like ordering.

Published:  Phys. Rev. Lett. 135, 206101 (2025). 

Techniques: Effective Hamiltonian, Monte Carlo, thin-film boundary conditions, surface modeling.