Yoshihisa Kamo

Magnetoresistive thin‐film sensor with permanent magnet biasing film

Magnetic characteristics have been investigated for a magnetoresistive thin‐film sensor biased using a permanent magnet thin film. Here, Co‐Pt thin film is applied to the device as a bias film. Such microlithographed Co‐Pt thin films show the same magnetic properties as as‐sputtered films. Biasing strength depends on the permanent magnet film thickness, its composition or magnetic properties, and the biasing angle. The output of the sensor is very high.

A new biasing method for shielded MR head

Reproduced signal waveform changes of magnetoresistive (MR) heads due to head wear are studied through experiments and computer simulations using the finite‐element method. The experiments are performed utilizing magnetic tapes and MR heads with permanent‐magnet and shunt bias. The change of reproduced signal waveform asymmetry is opposite in these biasing methods. Based on this result, we propose a new biasing MR head which has a structure combining current bias with permanent‐magnet bias, and present its advantages.