The effect of K and Na excess on the ferroelectric and piezoelectric properties of K0.5Na0.5NbO3 thin films

• Published in: Journal of physics. D, Applied physics Vol. 42; no. 21; pp. 215304 - 215304 (5)
• Main Authors: Ahn, C W, Lee, S Y, Lee, H J, Ullah, A, Bae, J S, Jeong, E D, Choi, J S, Park, B H, Kim, I W
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 07.11.2009; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric thin films; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Domain structure; hysteresis; Exact sciences and technology; Ferroelectricity and antiferroelectricity; Physics; Piezoelectricity and electromechanical effects; Switching phenomena; Stoichiometry; Potassium Sodium Niobates Mixed; Ferroelectricity; Chemical bath deposition; Piezoelectricity; Polycrystals; Ferroelectric switching; Leakage currents; Ferroelectric thin films; Ferroelectric hysteresis
• DOI: 10.1088/0022-3727/42/21/215304
• ISSN: 0022-3727

We have fabricated K0.5Na0.5NbO3 (KNN) thin films on Pt substrates by a chemical solution deposition method and investigated the effect of K and Na excess (0-30 mol%) on ferroelectric and piezoelectric properties of KNN thin film. It was found that with increasing K and Na excess in a precursor solution from 0 to 30 mol%, the leakage current and ferroelectric properties were strongly affected. KNN thin film synthesized by using 20 mol% K and Na excess precursor solution exhibited a low leakage current density and well saturated ferroelectric P-E hysteresis loops. Moreover, the optimized KNN thin film had good fatigue resistance and a piezoelectric constant of 40 pm V-1, which is comparable to that of polycrystalline PZT thin films.