Control of magnetic direction in multi-layer ferromagnetic devices by bias voltage
AssigneeThe University of Chicago
InventorsChun-Yeol You, Samuel D. Bader
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Abstract
A system for controlling the direction of magnetization of materials comprising a ferromagnetic device with first and second ferromagnetic layers. The ferromagnetic layers are disposed such that they combine to form an interlayer with exchange coupling. An insulating layer and a spacer layer are located between the first and second ferromagnetic layers. A direct bias voltage is applied to the interlayer exchange coupling, causing the direction of magnetization of the second ferromagnetic layer to change. This change of magnetization direction occurs in the absence of any applied external magnetic field.
Claims27
A system for controlling a magnetization direction of materials, comprising:
- a ferromagnetic device, including:
- a first electrode comprising a first ferromagnetic layer;
- a second electrode comprising a second ferromagnetic layer disposed adjacent the first ferromagnetic layer such that an interlayer exchange coupling is formed between the first and second ferromagnetic layers;
- an insulating layer located between the first and second electrodes;
- a spacer layer located between the first electrode and the second electrode;
- and
- voltage bias means sufficient for changing the interlayer exchange coupling without assistance from an external magnetic field, such that when the bias means applies a bias voltage to the ferromagnetic layers, the interlayer exchange coupling is affected and the direction of magnetization of the second ferromagnetic layer is altered.
In a system having controllable exchange coupled layers for altering a magnetization direction of a plurality of magnetic layers, including first and second ferromagnetic layers, an insulating material between the magnetic layers, and a spacer layer located between the first ferromagnetic layer and the insulating material, wherein an improvement comprises:
- means for applying a bias voltage across the coupled layers sufficient to cause the magnetic configuration of at least one of the magnetic layers to oscillate between a ferromagnetic and antiferromagnetic configuration without assistance from an external magnetic field.
A process of controlling the magnetization direction in a system with interlayer exchange coupling, comprising the steps of:
- providing first and second electrodes comprising ferromagnetic materials to form an interlayer exchange coupling;
- placing a spacer material between the first and second electrodes;
- placing an insulator between the first and second electrodes;
- and
- generating a bias voltage across the interlayer exchange coupling sufficient to alter a magnetization direction of at least one of the ferromagnetic materials without assistance from an external magnetic field.
Dependencies are inferred from the claim text.