GMR magnetic transducer with nano-oxide exchange coupled free layers

A disk drive comprising:

• a disk having a thin film of ferromagnetic material on a planar surface of the disk;
• a spindle rotatably supporting the disk;
• and
• a magnetic transducer having an air bearing surface supported over the planar surface of the disk, the magnetic transducer including:
• a first pinned layer structure having a first magnetization;
• a first nonmagnetic spacer layer adjacent to the first pinned layer structure;
• a first free layer including a ferromagnetic material disposed adjacent the first nonmagnetic spacer layer, the free layer having a second magnetization perpendicular to the first magnetization in the absence of an external field;
• an exchange coupling spacer structure including a ferromagnetic nano-oxide layer and second and third nonmagnetic spacer layers disposed on opposing sides of the ferromagnetic nano-oxide layer;
• a second free layer including a ferromagnetic material disposed parallel to the first free layer and separated from the first free layer by the exchange coupling spacer structure, the first and second free layers being exchanged coupled through the ferromagnetic nano-oxide layer and having a free layer magnetization perpendicular to the pinned layer magnetization in the absence of an external field;
• a fourth nonmagnetic spacer layer;
• and
• a second pinned layer structure disposed adjacent to the fourth nonmagnetic spacer layer on a side of the second free layer farthest away from the exchange coupling spacer structure and having the first magnetization.