Patent 5673220 Issued on September 30, 1997. Estimated Expiration Date: June 7, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A composition of materials having ferromagnetic and piezoelectric properties is disclosed. In the preferred embodiment, the composition of materials comprises a first layer of Pb.sub.(1-x-y) Cdx Fey and a second layer of Cr.sub.(1-z-w) Znz Tew where x, y, z and w are values within the ranges of 0.38ࣘxࣘ0.042, 0.08ࣘyࣘ0.094, 0.38ࣘzࣘ0.41, 0.28ࣘwࣘ0.31, and 0.25ࣘ(1-z-w)ࣘ0.32. Additionally, each of the layers contain the elements of Bi, O and S. A random-accessible, non-volatile memory built using the invented composition of materials is also disclosed. This memory provides for storing two independent bits of binary information in a single storage cell. Each cell comprises two orthogonal address lines formed on the opposite surface of a Si substrate, a composition of materials of the present invention formed over each of the address lines, and an electrode formed over each composition of materials. The data is stored electromagnetically and retrieved as a piezoelectric voltage.
Other References
"Matrix Addressing Scheme for 3-D Polarization Echo Memory", R.Y. Hung, IBM Technical Disclosure Bulletin, vol. 18, No. 7, Dec. 1975
"Threshold Switch Protected Ferroelectric Memory", W.R. Smith, IBM Technical Disclosure Bulletin, vol. 17, No. 12, May 1975
"Operating Characteristics of a Thin Film Memory", Jack I. Raffel, Journal of Applied Physics, Supplement to vol. 30, No. 4, Apr. 1959
"Magnetic Film Memory Design", J.I. Raffel et al., Proceedings of the IRE, 1961
"Properties of Magnetic Films for Memory Systems", E.M. Bradley, Journal of Applied Physics, Supplement to vol. 33, No. 3, Mar. 1962
"Some Properties of an Anisotropic Thin-Film-Waffle-Iron Memory Cell:", Bobeck et al., Journal of Applied Physics, vol. 37, No. 3, Mar. 1966
"Coupled-Film Memory Elements", Hsu Cheng, Journal of Applied Physics, vol. 38, No. 3, Mar. 1967
"The B8500-microsecond thin-film memory", Jones et al., Fall Joint Computer Conference, 1967
"Magnetic Film Memory Systems", Pohn et al., IEEE Transactions on Magnetics, June, 1968
"A Critical Review of Magnetic Recording Materials", Bate et al., IEEE Transactions on Magnetics, Dec. 196
June 7, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
