Magnetoresistive element and magnetic memory device

A magnetoresistive element comprising a ferromagnetic double tunnel junction having a stacked structure of a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a first antiferromagnetic layer/a third dielectric layer/a second dielectric layer/a fourth ferromagnetic layer;

• and
• the first and fourth ferromagnetic layers consisting of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy.

A magnetoresistive element comprising a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a second antiferromagnetic layer/a third ferromagnetic layer/a second dielectric layer/a fourth ferromagnetic layer/a third antiferromagnetic layer;

• and
• the first and fourth ferromagnetic layers or the second and third ferromagnetic layers consisting of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy.

A magnetoresistive element comprising a ferromagnetic double tunnel junction having a stacked structure of a first ferromagnetic layer/a first dielectric layer/a second ferromagnetic layer/a first nonmagnetic layer/a third ferromagnetic layer/a second nonmagnetic layer/a fourth ferromagnetic layer/a second dielectric layer/a fifth ferromagnetic layer;

• the second, third and fourth ferromagnetic layers adjacent to each other being antiferromagnetically coupled through the nonmagnetic layers;
• and
• the first and fifth ferromagnetic layers consisting of a Co-based alloy or a three-layered film of a Co-based alloy/a Ni—Fe alloy/a Co-based alloy.

A magnetic memory device comprising a first magnetization pinned layer whose magnetization direction is pinned, a first dielectric layer, a magnetic recording layer whose magnetization direction is reversible, a second dielectric layer, and a second magnetization pinned layer whose magnetization direction is pinned;

• the magnetic recording layer comprising a three-layered film of a magnetic layer, a nonmagnetic layer and a magnetic layer, the two magnetic layers constituting the three-layered film being anti-ferromagnetically coupled;
• and
• magnetization directions of the two magnetization pinned layers in regions in contact with the dielectric layer being substantially anti-parallel to each other.

A magnetoresistive element comprising a ferromagnetic double tunnel junction having a stacked structure of a first antiferromagnetic layer/a first ferromagnetic layer/a first tunnel insulator/a second ferromagnetic layer/a first nonmagnetic layer/a third ferromagnetic layer/a second nonmagnetic layer/a fourth ferromagnetic layer/a second tunnel insulator/a fifth ferromagnetic layer/a second antiferromagnetic layer;

• the second and third ferromagnetic layers being antiferromagnetically coupled through a first nonmagnetic layer;
• and
• the third and fourth ferromagnetic layers being antiferromagnetically coupled through a second nonmagnetic layer.