Single domain state laminated thin film structure for use as a magnetic layer of a transducing head

A transducing head having an air bearing surface, the transducing head comprising:

• a first magnetic layer;
• a second magnetic layer substantially parallel to the first magnetic layer;
• a third magnetic layer separated at the air bearing surface from the second magnetic layer by a gap and connected to the second magnetic layer opposite the air bearing surface;
• a magnetoresistive sensor positioned between the first and the second magnetic layers;
• and
• conductive coils positioned at least in part between the second and the third magnetic layers;
• wherein at least one of the first, the second, and the third magnetic layers is formed of a thin film structure comprising:
• a first ferromagnetic layer;
• a second ferromagnetic layer having a thickness-magnetic moment product substantially equal to a thickness-magnetic moment product of the first ferromagnetic layer, an easy axis of the second ferromagnetic layer being substantially parallel to an easy axis of the first ferromagnetic layer;
• a nonmagnetic spacer layer positioned between the first ferromagnetic layer and the second ferromagnetic layer;
• and
• a first bias layer positioned adjacent the first ferromagnetic layer.

A transducing head having an air bearing surface, the transducing head comprising:

• a first magnetic layer;
• a second magnetic layer substantially parallel to the first magnetic layer;
• a third magnetic layer separated at the air bearing surface from the second magnetic layer by a gap and in contact with the second magnetic layer opposite the air bearing surface;
• a magnetoresistive sensor positioned between the first and the second magnetic layers;
• and
• conductive coils positioned at least in part between the second and the third magnetic layers;
• wherein at least one of the first, the second, and the third magnetic layers comprises a plurality of thin film structures and a plurality of structure spacer layers interspersed between the plurality of thin film structures, wherein each of the plurality of thin film structures comprises:
• a first ferromagnetic layer;
• a second ferromagnetic layer having a thickness-magnetic moment product substantially equal to a thickness-magnetic moment product of the first ferromagnetic layer, an easy axis of the second ferromagnetic layer being substantially parallel to an easy axis of the first ferromagnetic layer;
• a nonmagnetic spacer layer positioned between the first ferromagnetic layer and the second ferromagnetic layer;
• and
• a first bias layer positioned adjacent the first ferromagnetic layer;
• wherein the plurality of thin film structures are arranged to alternate the first and second ferromagnetic layers.

In a transducing head having an air bearing surface and comprising:

• a bottom shield;
• a top shield;
• a read element positioned between the bottom shield and the top shield;
• a top pole separated at the air bearing surface from the top shield by a gap and in contact with the top shield opposite the air bearing surface;
• and conductive coils positioned at least in part between the top pole and the top shield;
• an improvement comprising the top pole being formed of a thin film structure comprising:
• a first ferromagnetic layer;
• a second ferromagnetic layer having a thickness-magnetic moment product substantially equal to a thickness-magnetic moment product of the first ferromagnetic layer, an easy axis of the second ferromagnetic layer being substantially parallel to an easy axis of the first ferromagnetic layer;
• a nonmagnetic spacer layer positioned between the first ferromagnetic layer and the second ferromagnetic layer;
• and a first bias layer positioned adjacent the first ferromagnetic layer.

In a transducing head having an air bearing surface and comprising:

• a magnetoresistive sensor;
• and
• at least one magnetic layer spaced away from the magnetoresistive sensor;
• an improvement comprising the at least one magnetic layer being formed of a thin film structure comprising:
• a first ferromagnetic layer;
• a second ferromagnetic layer having a thickness-magnetic moment product substantially equal to a thickness-magnetic moment product of the first ferromagnetic layer, an easy axis of the second ferromagnetic layer being substantially parallel to an easy axis of the first ferromagnetic layer;
• a nonmagnetic spacer layer positioned between the first ferromagnetic layer and the second ferromagnetic layer;
• and
• a first bias layer positioned adjacent the first ferromagnetic layer.