A dual spin valve (SV) sensor is provided with a longitudinal bias stack
sandwiched between a first SV stack and a second SV stack. The
longitudinal bias stack comprises an antiferromagnetic (AFM) layer
sandwiched between first and second ferromagnetic layers. The first and
second SV stacks comprise antiparallel (AP)-pinned layers pinned by AFM
layers made of an AFM material having a higher blocking temperature than
the AFM material of the bias stack allowing the AP-pinned layers to be
pinned in a transverse direction and the bias stack to be pinned in a
longitudinal direction. The demagnetizing fields of the two AP-pinned
layers cancel each other and the bias stack provides flux closures for
the sense layers of the first and second SV stacks.