Patent ID: 7436636

Claim:
A current perpendicular to plane (CPP) magnetoresistive sensor, comprising a first pinned layer structure; a second pinned layer structure; an in stack bias structure disposed between the first and second pinned layer structures; a first magnetic free layer disposed between the first pinned layer structure and the in stack bias structure; and a second magnetic free layer disposed between the second pinned layer structure and the in stack bias structure; the in stack bias structure further comprising: a first magnetic layer; a second magnetic layer; a third magnetic layer disposed between the first and second magnetic layers; a first non-magnetic coupling layer sandwiched between the first magnetic layer and the first free layer; a second non-magnetic coupling layer sandwiched between the second magnetic layer and the second free layer; a third non-magnetic coupling layer sandwiched between the first magnetic layer and the third magnetic layer; and a fourth non-magnetic coupling layer sandwiched between the second magnetic layer and the third magnetic layer; at least one of the first second and third magnetic layers comprising a layer of Ni sandwiched between first and second layers of NiFe.