The fixed magnetic layer where magnetization direction is locked on the thin film magnetic head null antiferromagnetism

摘要

PROBLEM TO BE SOLVED: To solve the problem where Barkhausen noise is apt to be generated since a hard bias layer generating an intensive bias magnetic field is formed below a free magnetic layer, and only a hard bias layer whose bias magnetic field is weak is formed on a side part of the free magnetic layer which are caused by large film thickness of an antiferromagnetic layer, in the conventional spin valve type thin film element in which a fixed magnetic layer, a nonmagnetic conducting layer and the free magnetic layer are laminated on the antiferromagnetic layer and the hard bias layer is formed on side surfaces of the four layers. SOLUTION: By forming a hard bias layer 6 on an antiferromagnetic layer 1, a horizontal surface 6' can be formed in a part higher than a lower surface 4' of a free magnetic layer 4 with small film thickness. Consequently, the hard bias layer of an h1 part which generates an intensive bias magnetic field is made to abut against a side surface of the free magnetic layer 4, magnetization of the free magnetic layer 4 becomes easy to be made a single magnetic domain in the X direction, and generation of Barkhausen noise can be reduced.