Magnetic read head using (FePt)100-xCux as a permanent magnet material

A device comprising:

• a first layer of ferromagnetic material having a magnetization direction that is substantially fixed in a first magnetization direction;
• a second layer of ferromagnetic material having a magnetization direction that is substantially rotatable;
• a nonmagnetic layer disposed between the first and second ferromagnetic layers;
• and
• a hard magnetic material element having a magnetization direction that is substantially fixed in a second magnetization direction, the hard magnetic material element magnetically coupled to the second ferromagnetic layer and biasing the second ferromagnetic layer in the second magnetization direction, wherein the hard magnetic material element comprises an FePtCu alloy.

A magnetic reader having a magnetic sensing structure, the magnetic sensing structure comprising:

• a first layer of hard magnetic material having a magnetization direction that is substantially fixed in a first magnetization direction;
• a second layer of ferromagnetic material having a magnetization direction that is substantially rotatable;
• a nonmagnetic layer disposed between the first hard magnetic and second ferromagnetic layers;
• and
• a hard magnetic material element having a magnetization direction that is substantially fixed in a second magnetization direction, the hard magnetic material element magnetically coupled to the second ferromagnetic layer and biasing the second ferromagnetic layer in the second magnetization direction,
• wherein either the first hard magnetic layer or the hard magnetic material element comprises an FePtCu alloy.