Freestanding films with electric field-enhanced piezoelectric coefficients
AssigneeDrexel University
InventorsWei-Heng Shih, Hongyu Luo, Christian Martorano, Wan Shih
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Abstract
A method to produce low-temperature sinterable powders which are then subsequently used to fabricate freestanding piezoelectric films with very large electric-field-enhanced piezoelectric response is provided. The −d31 coefficient for PMN-PT layers can be as high as 2000 pm/V, larger than that of commercial single crystalline PMN-PT bulk materials, at 10 kV/cm (or 20 V over the 20-micron film thickness). In contrast to single crystals, the polycrystalline freestanding films are easy to fabricate and can be made into any size. The films are also easily miniaturized. The method can be applied to nearly any piezoelectric material.
Claims20
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 coating of said coated particles to form a dispersion,
- calcining the dispersion to form a calcined product wherein the coating of the coated particles has at least partially reacted with said material in said solution, and
- suspending the calcined product in a precursor coating solution to form a precursor powder.
A polycrystalline ceramic material having −d31 of at least 1500 pm/V at around 10 kV/cm.
Dependencies are inferred from the claim text.