Behavior of Metal-Doped Silica Thin Films with Artificial-Lattice Structure A: Electro-Mechanical Properties

An artificial-lattice structure of silica-based thin film was investigated. Thin films with a periodic structure of nanometer order silica layers containing metal dopants performed like c-axis oriented piezoelectric thin film. Piezoelectricity, pyroelectricity, and an anomalous photovoltaic effect were observed in poled artificial-lattice silica films. The polarization was stabilized by this structure to prevent aging. Furthermore, under some deposition conditions, piezoelectricity was observed in as-deposited films without poling process. We believe the Pockels effect occurs in the artificial-lattice-structure silica thin films.