Planar capacitive structures based on ferroelectric barium titanate–stannate films on sapphire for microwave applications

The structural properties of ferroelectric barium titanate–stannate films on sapphire substrates and microwave characteristics of related planar capacitive elements have been investigated. The gas-medium composition during the film deposition has been established to affect significantly the crystal structure, phase composition, and electric characteristics of the films. The low dielectric loss and high controllability of planar capacitive elements based on barium titanate–stannate films in the frequency range of 2–60 GHz are demonstrated for the first time.