Adsorption-controlled growth of BiMnO3 films by molecular-beam epitaxy

We have developed the means to grow BiMnO3 thin films with unparalleled structural perfection by reactive molecular-beam epitaxy and determined its band gap. Film growth occurs in an adsorption-controlled growth regime. Within this growth window bounded by oxygen pressure and substrate temperature at a fixed bismuth overpressure, single-phase films of the metastable perovskite BiMnO3 may be grown by epitaxial stabilization. X-ray diffraction reveals phase-pure and epitaxial films with omega rocking curve full width at half maximum values as narrow as 11 arc sec (0.003 degrees). Optical absorption measurements reveal that BiMnO3 has a direct band gap of 1.1 +/- 0.1 eV. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3457786]