Textured K0.5Na0.5NbO3 Thin Films by Aqueous Chemical Solution Deposition on SrTiO3 Substrates for MEMS Applications

Abstract

Na0.5K0.5NbO3 (KNN) thin films were fabricated on (100) oriented SrTiO3 substrates by spin coating a stable environmentally friendly aqueous KNN precursor. Homogeneous films with an average grain size down to 60 nm were observed after heat treatment at 900 °C. The high degree of texture was confirmed by XRD. The intensity of the KNN (100) reflection for films on (100) oriented substrates increased with increasing sintering temperature up to 900 °C. The ferroelastic and piezoelectric properties of the film was confirmed by PFM. Local piezoelectric properties of selected films will be discussed in relation to the processing conditions, microstructure and orientation of the substrate.