Synthetic ferrimagnet reference layer for a magnetic storage device

A magnetic storage device comprising:

• a synthetic ferrimagnet reference layer;
• a data layer having a first and a second magnetic orientations;
• a tunnel layer between said reference layer and said data layer;
• said reference layer comprising:
• a first layer of magnetic material;
• a second layer of magnetic material;
• said first and said second layers operable to be magnetized to cause the net magnetic moment of the reference layer to be substantially zero;
• and
• a spacer layer between said first layer and said second layer, said spacer layer with dimensions to magnetically couple said first layer and said second layer in opposite directions;
• said reference layer having two stable magnetic orientations, a first in which said first layer is in a first direction and said second layer is in an opposite direction and a second stable state in which said first layer is in said opposite direction and said second layer is in said first direction, said directions being substantially orthogonal to an applied magnetic field.

A method of operating a magnetic storage device, said method comprising:

• a) storing a bit in said device by applying a magnetic field to a data layer in said device to create a magnetic orientation in said data layer;
• b) applying a magnetic field to a reference layer having first and second layers with substantially the same coercivity and that are magnetically coupled in opposite directions, said applied magnetic field establishing a magnetic orientation in said first layer of said reference layer that is substantially orthogonal to said applied magnetic field;
• and
• c) measuring the resistance between said first layer and said data layer to determine the magnetic orientation of said data layer, wherein the bit stored in said storage device is determined.

A magnetic storage device comprising:

• an array of storage cells, said cells comprising:
• a first layer of magnetic material having first and second magnetic orientations;
• a second layer of magnetic material having first and second magnetic orientations;
• said first and said second layers having substantially the same coercivities;
• a spacer layer between said first and said second layers, said spacer layer for magnetically coupling said first and second layers in opposite directions, wherein said magnetic orientations of said first and said second layers tend to be substantially orthogonal to the direction of an applied magnetic field.

A synthetic ferrimagnet reference layer for a magnetic storage device, said reference layer comprising:

• a plurality of layers of magnetic material having first and second magnetic orientations;
• at least one spacer layer, said at least one spacer layer between adjacent layers of said plurality of layers, said at least one spacer layer of suitable dimensions to magnetically couple said adjacent layers in opposite directions;
• and
• said plurality of layers of magnetic material operable to be magnetized to cause the net magnetic moment of the reference layer to be substantially zero.