Interband transitions in epitaxial ferroelectric films ofNaNbO3

M. Tyunina, D. Chvostova, L. D. Yao, A. Dejneka, T. Kocourek, M. Jelinek, S. van Dijken
2015 Physical Review B  
The interband optical transitions in cube-on-cube-type epitaxial ferroelectric NaNbO 3 thin films and a reference antiferroelectric NaNbO 3 crystal are studied in the spectral range of 0.74-9 eV using variable-angle spectroscopic ellipsometry. The energies and the types of the transitions in the films are found to differ significantly from those in the crystal and to vary with epitaxial strain. The results are discussed in terms of epitaxial effects, including higher crystal symmetry,
more » ... symmetry, anisotropic lattice strain, and ferroelectric polarization in the NaNbO 3 films compared to the crystal.
doi:10.1103/physrevb.92.104101 fatcat:6zfdafdjdzc6nej2nlsqrxepjy