Paul E. Anderson

Heusler alloy based current-perpendicular-to-the-plane giant magnetoresistance heads for high density magnetic recording

Narrow-track current-perpendicular-to-the-plane giant magnetoresistive heads containing Heusler alloy layer have been fabricated utilizing an abutted junction hard bias design. The head performance has been tested quasistatically and dynamically under high density recording conditions using a perpendicular magnetic recording media.

Use of a permanent magnet in the synthetic antiferromagnet of a spin-valve

A spinvalve using a permanent magnet as the pinned layer in a synthetic antiferromagnet of a spinvalve is described here. Permanent magnet materials can have the following advantages over antiferromagnetic materials: superior corrosion resistance, a large switching field even at relatively high temperatures, and not needing a high temperature anneal to set its magnetic orientation. The giant magnetoresistance, high field switching, and switching at high temperatures was investigated for various spinvalves using the following film stacks as the pinned layer: CoCrPt (CCP); CCP\CoFe, CCP\Ru\CoFe; and CCP\CoFe\Ru\CoFe. It was found that a thin CoFe layer between the CCP and Cu and between the CCP and Ru enhances giant magnetoresistance and antiferromagnetic coupling, respectively. When the CCP is used in a synthetic antiferromagnet, the CCP coercivity increases compared to a single layer of CCP. The switching field of CCP at 425 °C is >1000 Oe, at the same temperature the switching field for an antiferromagne...

Ion beam deposition of permanent magnet layers for liftoff processes

Thin film permanent magnet layers of Cr/CoCrPt were prepared by ion beam deposition in a Veeco IBD-350 tool. The magnetic properties were measured as a function of deposition angle, deposition energy, assist energy, and the underlayer and permanent magnet thicknesses. It was found that higher deposition energies and angles (from normal) resulted in larger coercivities. Increasing the assist energy also helped increase the coercivity. The coercivities were in the range of 1400–2100 Oe depending on the deposition conditions, for a Cr-50 A/CoCrPt-250 A film. The squareness, S (the ratio of remnant magnetization to saturation magnetization) and Mrt (remnant magnetization and film thickness product) for these films were about 0.85 and 1.3 memu/cm2, respectively. It was found that underlayers of Cr as thin as 25 A could be used, without significant degradation of magnetic properties. The coercivity had a broad peak between 100 and 200 A of CoCrPt, above which the coercivity gradually decreased. θ–2θ x-ray diffr...