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Magnetic Memory Device Utilizing Coupled Film

IP.com Disclosure Number: IPCOM000093228D
Original Publication Date: 1967-Jul-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Judge, JS: AUTHOR [+3]

Abstract

These layered materials represent magnetic memory devices. The device at A consists of layer 1 of low-coercivity ferromagnetic material, layer 3 of high-coercivity ferromagnetic material and interleaved layer 2 of antiferromagnetic material. In operation, as an element capable of exhibiting two different states of magnetization, it is first, as at A1, subjected to an applied directional magnetic field and simultaneously cooled below the Neel point of layer 2. This results in the separate coupling of each layer 1 and 3 to a lattice layer 2, causing the thus magnetized system to exhibit a high degree of magnetic stability. The element can be caused to assume a second state of magnetization by raising it to a temperature near the Neel point of layer 2 in the absence of an applied field as at A2.

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Magnetic Memory Device Utilizing Coupled Film

These layered materials represent magnetic memory devices.

The device at A consists of layer 1 of low-coercivity ferromagnetic material, layer 3 of high-coercivity ferromagnetic material and interleaved layer 2 of antiferromagnetic material. In operation, as an element capable of exhibiting two different states of magnetization, it is first, as at A1, subjected to an applied directional magnetic field and simultaneously cooled below the Neel point of layer 2. This results in the separate coupling of each layer 1 and 3 to a lattice layer 2, causing the thus magnetized system to exhibit a high degree of magnetic stability. The element can be caused to assume a second state of magnetization by raising it to a temperature near the Neel point of layer 2 in the absence of an applied field as at A2. This causes layer 2 to become disordered and act as a nonferromagnetic material. This, in turn, results in a condition in which layer 3 couples with layer 1, causing layer 1 to switch into antiparallel alignment with layer 3. This new state is then stabilized by once more lowering the temperature of the element below the Neel point of layer 2 as at A3.

An alternative device is shown at B. The device consists of layer 4 of ferromagnetic material and layer 5 of antiferromagnetic material. In operation, the element is cooled below the Neel point of layer 5 in an applied field, as at B1, with the resulting coupling of layers 4 and 5....