Yasuhiro Kitade

Study of exchange-coupled bias field in Ni-Fe/Pd-Pt-Mn thin films

We propose a new Pd-Pt-Mn antiferromagnetic material with high corrosion resistance. This material yields a high Hex to a coupled Ni-Fe film by annealing at a temperature lower than 230/spl deg/C. This material will be suitable for the pinning layer of a spin-valve film and the domain control biasing layer of an AMR head.

Patterned media fabricated by lithography and argon-ion milling

Using continuous film prepared by lower gas sputtering, a dot array with a more stable single domain was achieved. The requirements for magnetic properties of patterned media were different from that of perpendicular continuous-film media. The switching field distribution in dot arrays depends on fluctuation in dot size. The smallest size of dot arrays, fabricated by most simple method as lithography and ion-milling, is 50 nm.

Giant magnetoresistance effect in CoNiFe/Cu spin valves

We studied the MR effect of a spin valve when using CoNiFe as the magnetic layer, yielding zero magnetostriction. An MR ratio of 6.8% with a saturation field of 3.6 Oe was obtained when using a Co/sub 45/Ni/sub 30/Fe/sub 25/ composition. Also we investigated the heat stability of this spin valve. A patterned, unshielded CoNiFe spin valve sensor was fabricated, and it transfer curve showing greater sensitivity than NiFe/Cu spin valves and exhibited no hysteresis.