Magnetic tunnel junction device and method including a tunneling barrier layer formed by oxidations of metallic alloys

A method of manufacturing a magnetic tunnel junction device, comprising:

• forming a first electrode comprising a free ferromagnetic layer;
• forming a tunnel barrier layer on said free ferromagnetic layer, the tunnel barrier layer being formed by oxidizing a thin metallic alloy layer of Ni and another non-magnetic material;
• and
• forming a second electrode comprising a fixed ferromagnetic layer on said tunnel barrier layer.

A magnetic tunnel junction read head arrangement connected to electrical circuitry that detects a change in electrical resistance of the read head in the presence of an applied magnetic field, the read head arrangement comprising:

• a first electrical conducting lead layer;
• and
• a second electrical conducting lead layer;
• and
• a magnetic tunnel junction formed between and in contact with the first and second electrical conducting lead layers to form an electrically conductive path from the first lead layer to the second lead layer through the magnetic tunnel junction, the magnetic tunnel junction comprising:
• a first electrode comprising a fixed ferromagnetic layer having a magnetization fixed in a particular direction in the presence of an applied magnetic field;
• a second electrode comprising a free ferromagnetic layer having a magnetization that is free to rotate in the presence of an applied magnetic field;
• and
• a tunnel barrier layer, sandwiched between said fixed ferromagnetic layer and said free ferromagnetic layer, for permitting tunneling current to flow in a direction generally perpendicular to the fixed and free ferromagnetic layers, the tunnel barrier layer including an oxidized thin metallic alloy layer of Ni and another non-magnetic material.