SPIN VALVE MAGNETORESISTANCE SENSOR AND THIN-FILM MAGNETIC HEAD

PROBLEM TO BE SOLVED: To realize a high recording density by securing a high magnetoresistance change rate and a sensor sensitivity, related to a synthetic spin valve MR sensor having a pin magnetic layer of multi-film structure. SOLUTION: A free magnetic layer 7, a pin magnetic layer 5 comprising first and second ferromagnetic films 51 and 53 which, laminated with a magnetic coupling film 52 in between, are antiferromagnetically coupled condition each other, a non-magnetic conductive layer 6 sandwiched between both magnetic layers, and an antiferromagnetic layer 4 adjoining the pin magnetic layer are laminated on a substrate, while the first ferromagnetic film adjoining the antiferromagnetic layer formed of Co-based material of high specific resistance. Related to the first and second ferromagnetic films, when the products of a saturation magnetization and a film thickness are substantially equal, the magnetic moment of the entire pin magnetic layer apparently becomes 0, the magneto-static action on the free magnetic layer is eliminated or reduced. Thus, the shunt of sense current to the first ferromagnetic is suppressed, a high magnetoresistance change rate can be obtained.