Solid-phase epitaxial film growth and optical properties of a ferroelectric oxide, Sr2Nb2O7

High-quality epitaxial films of a ferroelectric oxide Sr2Nb2O7 were successfully fabricated by solid phase epitaxy (SPE) on (110) LaAlO3 single crystal substrates. In the SPE method, amorphous Sr-Nb-O films are first deposited by pulsed laser deposition at room temperature and then annealed in vacuum at elevated temperatures, resulting in the crystallization of Sr2Nb2O7 with highly ordered atomic arrangement and an atomically flat surface. The refractive index of the resultant film was 2.1, indicating that the dielectric permittivity of the film was in between 20 and 80, which corresponds well with that of single crystal Sr2Nb2O7, demonstrating the effectiveness of the SPE method for the fabrication of high-quality epitaxial films of Sr2Nb2O7. Published by AIP Publishing.