STRESS-INDUCED ANISOTROPY EFFECT FOR SAL FILMS IN MAGNETORESISTIVE ELEMENTS

The stress configuration of SAL (soft adjacent layer)-biased magnetore sistive (MR) elements has been analyzed, in order to study the stress- induced anisotropy effect on the MR transfer characteristics. The stre ss analysis, on the basis of stress measurement results in the single- layer sheet films that formed the MR elements, shows that anisotropic tensile stress of around 100 to 300 MPa is induced in the element heig ht direction in the SAL fdm with an open-pattern edge structure. Furth ermore, we calculated the MR transfer curves using a micromagnetic mod el for samples with different saturation magnetostriction constant (la mbda(S)) value for SAL films. Assuming anisotropic tensile stress of 3 00 MPa in the element height direction throughout the entire track reg ion, a desirable lambda(S) value for SAL films is in the range from +1 x10(-6) to -2x10(-6), because the stress-induced anisotropy in the SAL does not seriously affect the MR transfer curves.