MR reader sensitivity and SAL magnetic anisotropy

Two kinds of abutted junction magnetoresistive recording heads with different SAL effective magnetic anisotropy were manufactured. Experimental results show that heads with near zero magnetostriction have stable performance. However, heads with very positive (10^-6 ) magnetostriction show multi-domain state, bumpy microtracks. The amplitude of this head with highly magnetostrictive SAL depends on the initial SAL magnetic state with respect to the bias current. All these abnormalities are mainly caused by the effective magnetic anisotropy of the SAL being perpendicular instead of parallel to the ABS of the SAL layer