Abstract: Electronic and optical (or photonic) devices with variable or switchable properties and methods used to form these devices, are disclosed. More specifically, the present invention involves forming layers of conductive material and dielectric material or materials with varying conductivity and indexes of refraction to form various electronic and optical devices. One such layer of adjustable material is formed by depositing epitaxial or reduced grain boundary barium strontium titanate on the C-plane of sapphire.