MAGNETO-RESISTIVE HEAD BASED ON SPIN VALVE EFFECT AND MAGNETIC RECORDING AND REPRODUCING DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a spin valve sensor or head of high sensitivity which is stable to large external magnetic fields, has no antiferroelectric exchange bond layers and has laminated Fourier fixed layers. SOLUTION: The second ferromagnetic layers of the magneto-resistive head based on the spin valve effect having first ferromagnetic layers 44 and 45 and second ferromagnetic layers and conductive and nonmagnetic spacer layers 43 between the first and second ferromagnetic layers are composed of two sheets of ferromagnetic films A52 and ferromagnetic films B54 which are antiferromagnetically bonded to each other and antiferromagnetic films 53 for separating two sheets of the ferromagnetic films A52 and B54. The induction magnetic anisotropy constants of the ferromagnetic films A52 and the ferromagnetic films B54 are specified to >=2×103 (J/m3) and the saturated magnetostriction constants of the ferromagnetic films A52 and the ferromagnetic films B54 are specified to positive values. The compositions of the ferromagnetic films A52 and the ferromagnetic films B54 may be composed of Co100-Y-ZFeYNiZ (at%) Y>=5 Z<=20 Y+Z<=70.