Freestanding films with electric field-enhanced piezoelectric coefficients

A method for fabricating low-temperature, sinterable polycrystalline ceramic comprising the steps of:

• dispersing coated particles in a solution of a material reactive with the coated particles to form a dispersion,
• drying the dispersion to provide a powder,
• calcining the powder to form a calcined product wherein the coating of the coated particles has at least partially reacted,
• suspending the calcined product in a precursor solution for a material reactive with the calcined product,
• forming a powder of the calcined product and the material reactive with the calcined product from said precursor solution and suspended calcined product,
• providing a slurry of said powder of the calcined product and the material reactive with the calcined product, a binder, a dispersing resin and a solvent,
• tape casting the slurry on a carrier tape to form a layer of the calcined product and the material reactive with the calcined product,
• separating the layer of the calcined product and the material reactive with the calcined product from the carrier tape to provide a freestanding film of the calcined product and the material reactive with the calcined product, and
• reactive sintering the freestanding film of the calcined product and the material reactive with the calcined product, under conditions whereby the calcined product reacts with the material reactive with the calcined product to provide a sintered freestanding polycrystalline ceramic film.