Abstract
Owing to their large tunneling magnetoresistance effect, metal-nonmetal granular alloy films are now promised as useful materials for high-performance magnetic heads. In general, the granular films exhibit large TMR effect only with a considerably large magnetic field of the order of several kOe, One effective method is the use of granular-in-gap(GIG) structure. It is demonstrated that Fe_<20>Ni_<80> films formed by oblique sputtering have well-defined nano-furrow structures, and Co-Sm-O granular films deposited onto such FeNi films. MR ratio of Co-Sm-O granular film value about 6.6% at 12kOe. MR ratio of NiFe-CoSmO composite film value about 3.0% at 25Oe. From this value, the field sensitivity of Δρ/ρ_0 of the composite film is evaluated to be about 200 times higher than that of the Co-Sm-O single-layer film.
