Patent ID: 7072156

Claim:
A method for setting a remanent magnetization of a bias subassembly for biasing a free layer of a magnetic sensor, the method comprising: providing within the bias subassembly a first bias layer of ferromagnetic material having a coercivity Hc1 and providing a first bias to the free layer; providing within the bias subassembly a second bias layer of ferromagnetic material having a coercivity Hc2 greater than Hc1 and providing a second bias to the free layer; providing within the bias subassembly a decoupling layer disposed between the first and second bias layers to substantially eliminate exchange coupling between the first and second bias layers; and applying a first bias magnetic field having a magnetic field strength H1 to the bias subassembly, wherein H1 is greater than Hc1 and H1 is less than Hc2; whereby the first bias is altered, and the second bias is substantially unaltered.