Dual free layer magnetic reader having a rear bias structure including a soft bias layer

摘要

A method and system provide a magnetic read apparatus having an air-bearing surface (ABS). The read apparatus includes a read sensor, a side bias structure and a rear magnetic bias structure. The read sensor includes first and second free layers, a spacer layer and a rear surface opposite to the ABS. The spacer layer is nonmagnetic and between the first and second free layers. The side bias structure is adjacent to the side surface(s) and magnetically biases the first and second free layers to be antiferromagnetically aligned. The rear magnetic bias structure biases the free layers in a scissor mode. The read sensor is between the ABS and the rear magnetic bias structure. The rear magnetic bias structure includes a rear soft magnetic bias structure having a saturation magnetization-thickness product of at least one milli-emu/cm2 and not more than three milli-emu/cm2.

主权项

1. A magnetic read apparatus having an air-bearing surface (ABS) comprising:
a read sensor including a first free layer having a first upper surface and a first lower surface, a spacer layer, and a second free layer having a second lower surface and a second upper surface, the spacer layer being nonmagnetic and residing between the upper surface of the first free layer and the lower surface of second free layer, the read sensor having a rear surface opposite to the ABS; a side bias structure adjacent to at least one side surface of the read sensor, the side bias structure being configured to magnetically bias the first free layer and the second free layer to be antiferromagnetically aligned; and a rear magnetic bias structure configured to bias the first free layer and the second free layer in a scissor mode, the read sensor being between the ABS and the rear magnetic bias structure, the rear magnetic bias structure including a rear soft magnetic bias structure having a saturation magnetization-thickness product of at least one milli-emu/cm2 and not more than three milli-emu/cm2.