Thin film bismuth iron oxides useful for piezoelectric devices
AssigneeThe Regents of the University of California
InventorsRobert J. Zeches, Lane W. Martin, Ramamoorthy Ramesh
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Abstract
The present invention provides for a composition comprising a thin film of BiFeO3 having a thickness ranging from 20 nm to 300 nm, a first electrode in contact with the BiFeO3 thin film, and a second electrode in contact with the BiFeO3 thin film; wherein the first and second electrodes are in electrical communication. The composition is free or essentially free of lead (Pb). The BFO thin film is has the piezoelectric property of changing its volume and/or shape when an electric field is applied to the BFO thin film.
Claims26
A device comprising a composition comprising a thin film of BiFeO3 (BFO) having a thickness ranging from 20 nm to 300 nm, a first electrode in contact with the BiFeO3 thin film in a tetragonal-like phase, and a second electrode in contact with the BiFeO3 thin film;
- wherein the first and second electrodes are in electrical communication;
- wherein the device is configured such that the thin film is capable of a shape change or deformation of up to about 10% of its original dimension.
A composition comprising a thin film of BiFeO3 (BFO) having a thickness ranging from 20 nm to 300 nm, a first electrode in contact with the BiFeO3 thin film in a tetragonal-like phase, and a second electrode in contact with the BiFeO3 thin film;
- wherein the first and second electrodes are in electrical communication;
- wherein the composition comprises a plurality of pairs of electrodes;
- wherein the pairs of electrodes are in a series or an array, and each pair of electrode is in electrical communication.
A method of deforming a BiFeO3 (BFO) thin film comprising:
- (a) providing a device comprising a composition comprising a thin film of BFO having a thickness ranging from 20 nm to 300 nm, a first electrode in contact with the BFO thin film, and a second electrode in contact with the BFO thin film;
- wherein the first and second electrodes are in electrical communication, wherein the device is configured such that the thin film is capable of a shape change or deformation of up to about 10% of its original dimension;
- and (b) creating an electric field through the thin film, such that the thin film is deformed wherein the BFO thin film changes from a tetragonal-like phase into a rhombohedral-like phase.
A method of manufacturing a device comprising a piezoelectric composition, comprising:
- (a) providing a first electrode layer on a substrate, (b) depositing a ferroelectric layer on the first electrode layer, and (c) depositing a second electrode layer on the ferroelectric layer;
- wherein the ferroelectric layer is a BiFeO3 (BFO) thin film in a tetragonal-like phase;
- wherein the device is configured such that the thin film is capable of a shape change or deformation of up to about 10% of its original dimension.
Dependencies are inferred from the claim text.