Magnetic and electrical properties of NiFe-oxide mixture films

In order to improve the performance of magnetoresistive heads, higher saturation flux density Bs and higher resistivity /spl rho/ are preferable for Soft Adjacent Layer (SAL). NiFe-oxide (oxide=SiO/sub 2/, Al/sub 2/O/sub 3/, ZrO/sub 2/ and Ta/sub 2/O/sub 5/) mixture films were investigated for SAL. Among these films, the NiFe-ZrO/sub 2/ system is preferable because of its high Bs /spl rho/ and low coercivity. The stability of the NiFe-ZrO/sub 2/ system at 250/spl deg/C was also investigated, which shows that Bs and /spl rho/ change by annealing and the changes increase with ZrO/sub 2/ content. MR devices of 3.2 /spl mu/m width and 2.8 /spl mu/m height were fabricated and transfer curves were measured. The maximum output voltage of the device in which NiFe-12mol% ZrO/sub 2/ was employed was 23% larger than the calculated value for the device in which NiFe-Nb (Bs /spl rho/=60 Tesla /spl mu//spl Omega/cm) was assumed to be employed.