Growth of Epitaxial {100}-Oriented KNbO3-NaNbO3 Solid Solution Films on (100)cSrRuO3//(100)SrTiO3 by Hydrothermal Method and Their Characterization

Films of solid solution in KNbO3-NaNbO3 (KNN) were deposited at 240 degrees C on (100)(c)SrRuO3//(100)SrTiO3 substrates by the hydrothermal method. (KxNa1-x)NbO3 films with x = 0-1.0 were synthesized by changing the fraction of KOH in a solution of KOH and NaOH. The x in (KxNa1-x)NbO3 continuously changed with the volume fraction of KOH, while the deposition amount strongly depended on x. Epitaxial films with {100} orientation were obtained in the entire composition range and their out-of-plane lattice spacing changed with x. All the films showed ferroelectricity and their remanent polarization became larger than what above x = 0.58. (C) 2011 The Japan Society of Applied Physics