Abstract A quadristable ferroelectric device comprises a ferroelectric material with at least two independently reversible polarization components and single-crystal domains. At least one set of electrodes are positioned to apply electric fields to singlecrystal domains of the ferroelectric material at such angle to said reversible polarization components that a first electric field can ferroelectrically polarize and repolarize both said reversible polarization components and a second electric field can reverse one said reversible polarization component without reversing the other said reversible polarization component. Preferably, the ferroelectric material of the quadristable ferroelectric device is (010) crystallographically oriented bismuth titanate and the angle of the set of electrodes is between about 30* and 60* and most desirably between about 40* and 50* to the a and c crystallographic axes of the singlecrystal domains. Further, it is preferable that each set of electrodes comprise three elongated electrodes parallel to and spaced apart from each other with the driving potential to apply the electric field applied at either the center or the pair of outer electrodes.
A quadristable ferroelectric device as set forth in claim 1 wherein: the ferroelectric material is bismuth titanate.
Claim 2
Dependent Claim
40 words
A quadristable ferroelectric device as set forth in claim 2 wherein: the set of electrodes apply the electric fields at between about 30* and 60* to the a and c crystallographic axes of the single-crystal domains of the bismuth titanate.
Claim 3
Dependent Claim
40 words
A quadristable ferroelectric device as set forth in claim 2 wherein: the set of electrodes apply the electric fields at between about 40* and 50* to the a and c crystallographic axes of the single-crystal domains of the bismuth titanate.
Claim 4
Dependent Claim
66 words
A quadristable ferroelectric device comprising: a. a substrate; b. an epitaxially grown bismuth titanate film attached to said substrate having untwinned (010) crystallographically oriented regions; c. at least one set of electrodes fastened to the bismuth titanate film to apply electric fields through said film at about between 30* and 60* to the a and c crystallographic axes of said untwinned regions of the bismuth titanate.
Claim 5
Dependent Claim
20 words
A quadristable ferroelectric device as set forth in claim 5 wherein: the substrate is a (110) crystallographically oriented spinel crystal.
Claim 6
Dependent Claim
46 words
A quadristable ferroelectric device as set forth in claim 5 wherein: each set of electrodes comprises three electrodes parallel to and spaced apart from each other whereby the electric fields applied through the ferroelectric material are in opposite directions between electrodes of said set of electrodes.
Claim 7
Dependent Claim
41 words
A quadristable ferroelectric device as set forth in claim 7 wherein: the electric fields applied through the ferroelectric material are at between about 40* and 50* to the a and c crystallographic axes of said untwinned regions of the bismuth titanate.
Claim 8
Dependent Claim
74 words
A quadristable ferroelectric device as set forth in claim 7 comprising in addition: d. a photosensitive layer attached to the centrally positioned electrode of set of electrodes is capable of electrically conducting when light radiation is incident thereon; and e. a translucent electrode attached to the photosensitive layer and capable of applying a potential to said centrally positioned electrode of at least one said set of electrodes when the photosensitive material is light activated.