Accession Number : ADD017948

Title :   Ultra High Density, Non-Volatile Ferromagnetic Random Access Memory.

Descriptive Note : Patent, Filed 1 Oct 93, patented 19 Dec 95,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Prinz, Gary A

Report Date : 19 Dec 1995

Pagination or Media Count : 15

Abstract : A random access memory element utilizes giant magnetoresistance. The element includes at least one pair of ferromagnetic layers sandwiching a nonmagnetic conductive layer. At least one of the two ferromagnetic layers has a magnetic moment oriented within its own plane. The magnetic moment of at least the first ferromagnetic layer of the pair has its magnetic moment oriented within its own plane and is typically fixed in direction during use. The second ferromagnetic layer of the pair has a magnetic moment which has at least two preferred directions of orientation. These preferred directions of orientation may or may not reside within the plane of the second ferromagnetic layer. The bit of the memory element may be set by applying to the element a magnetic field which orients the magnetic moment of the second ferromagnetic layer in one or the other of these preferred orientations. Once the bit is set, the value of the determined by the relative alignment of the magnetic moments of the first and second ferromagnetic layers. This value may be read by applying an interrogating current across the memory element, perpendicular to the plane within which the magnetic moment of the first ferromagnetic layer is oriented, and observing the variation in resistance. These ferromagnetic elements may be fabricated using conventional photolithography. Groups of these ferromagnetic element may be organized into word trees and other arrays.

Descriptors :   *RANDOM ACCESS COMPUTER STORAGE, *NONVOLATILE MEMORIES, *PATENTS, MAGNETIC FIELDS, POLARIZATION, HIGH DENSITY, DATA STORAGE SYSTEMS, FERROMAGNETIC MATERIALS, PHOTOLITHOGRAPHY, MAGNETORESISTANCE, ANTIFERROMAGNETISM, MAGNETIC MOMENTS, THIN FILM STORAGE DEVICES, MAGNETIC FILM MEMORIES

Subject Categories : Computer Hardware
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE