Hard disk system incorporating a current perpendicular to plane magneto-resistive effect device with a spacer layer in the thickness range showing conduction performance halfway between OHMIC conduction and semi-conductive conduction

摘要

The thickness of the semiconductor layer forming a part of the spacer layer is set in the thickness range for a transitional area showing conduction performance halfway between ohmic conduction and semi-conductive conduction in relation to the junction of the semiconductor layer with the first nonmagnetic metal layer and the second nonmagnetic metal layer. This permits the specific resistance of the spacer layer to be greater than that of an ohmic conduction area, so that spin scattering and diffusion depending on a magnetized state increases, resulting in an increase in the MR ratio. The CPP-GMR device can also have a suitable area resistivity (AR) value. If the device can have a suitable area resistivity and a high MR ratio, it is then possible to obtain more stable output power in low current operation. The device is also lower in resistance than a TMR device, so that significant noise reductions are achievable.