Optical band gap of BiFeO3 grown by molecular-beam epitaxy

Authors

J. F. Ihlefeld, Pennsylvania State University
N. J. Podraza, Pennsylvania State University
Z. K. Liu, Pennsylvania State University
R. C. Rai, University of Tennessee
X. Xu, University of Nebraska-LincolnFollow
T. Heeg, Research Centre Julich
Y. B. Chen, University of Michigan-Ann Arbor
J. Li, University of Toledo
R. W. Collins, University of Toledo
J. L. Musfeldt, University of Tennessee
X. Q. Pan, University of Michigan-Ann Arbor
J. Schubert, Research Centre Julich
R. Ramesh, University of California - Berkeley
D. G. Schlom, Pennsylvania State UniversityFollow

Date of this Version

2008

Document Type

Article

Citation

Appl. Phys. Lett. 92, 142908 (2008)

Comments

Used by permission.

Abstract

BiFeO₃ thin films have been deposited on (001) SrTiO₃ substrates by adsorption-controlled reactive molecular-beam epitaxy. For a given bismuth overpressure and oxygen activity, single-phase BiFeO₃ films can be grown over a range of deposition temperatures in accordance with thermodynamic calculations. Four-circle x-ray diffraction reveals phase-pure, epitaxial films with w rocking curve full width at half maximum values as narrow as 29 arc sec (0.008°). Multiple-angle spectroscopic ellipsometry reveals a direct optical band gap at 2.74 eV for stoichiometric as well as 5% bismuth-deficient single-phase BiFeO₃ films.