Synthesis of oriented Ba2NaNb5O15 (BNN) thin films from an alkoxy-derived precursor

Ba2NaNb5O15 (BNN) thin films with a tungsten bronze structure were fabricat ed using a precursor solution that was synthesized from barium, sodium, and niobium alkoxides. Highly (002)-oriented BNN films were prepared successfu lly on Pt(100)MgO(100) substrates at 700 degrees C, using a BNN underlayer. X-ray pole-figure measurement showed that the BNN films that crystallized on Pt(100)/MgO(100) substrates had two in-plane orientations. The remanent polarization and coercive field of the BNN film (thickness of 1.0 mu m) tha t was crystallized at 700 degrees C were 12.3 mu C/cm(2) and 101 kV/cm, res pectively, at -150 degrees C (123 K). BNN films on fused silica substrates exhibited second harmonic generation upon irradiation with 1064 nm light.