We studied the ferroelectric and ferromagnetic properties of compressive strained and unstrained BiMnO3 thin films grown by rf-magnetron sputtering. BiMnO3 samples exhibit a 2D cube-on-cube growth mode and a pseudo-cubic struc-ture up to a thickness of 15 nm and of 25 nm when deposited on (001) SrTiO3 and (110) DyScO3, respectively. Above these thicknesses we observe a switching to a 3D island growth and a simultaneous structural change to a monoclinic structure characterized by a (00l) orientation of the monoclinic unit cell. While ferromagnetism is observed below Tc = 100 K for all samples, signatures of room temperature ferroelectricity were found only in the pseudo-cubic ultra-thin films, indicating a correlation between electronic and structural orders.
@article{arxiv.1306.1192,
title = {Ferromagnetism and Ferroelectricity in epitaxial ultra-thin BiMnO3 films},
author = {G. M. De Luca and D. Preziosi and F. Chiarella and R. Di Capua and S. Gariglio and S. Lettieri and M. Salluzzo},
journal= {arXiv preprint arXiv:1306.1192},
year = {2013}
}