(NiFe / CoFe) / Cu / CoFe Spin - Valve 박막의 자기저항 특성

다국어 초록 (Multilingual Abstract)

The MR ratios and the exchange biasing field and interlayer coupling field were investigated in Ni_(81)Fe_(19)/Co_(90)Fe_(10)/Cu_(90)Fe_(10) spin-valve sandwiches grown on anti ferromagnetic NiO films as a function of the NiO thickness, the thickness of Cu and pinning layer Co_(90)Fe_(10). The spin-valve sandwiches were deposited on the Corning glass 7059 by means of the 3-gun dc and 1-gun rf magnetron sputtering at a 5 mtorr partial Ar pressure and room temperature. The deposition field was 50 Oe. The MR curve was measured by the four-terminal method with applied magnetic field up to 500 Oe perpendicular to the direction of a current in the plane. The coercivity of magnetic soft bilayer [NiFe/CoFe] (90 Å) decreased dramatically to less than 10 Oe when the NiFe/CoFe bilayer used an NiFe bilayer thicker than 20 Å. SO NiFe layer improved the softmagnetic properties in the NiFe/CoFe bilayer. The GMR ratio and the magnetic field sensitivity of the spin-valve film Ni_(91)Fe_(19)(40 Å)/Co_(90)Fe_(10)(50 Å)/Cu(30 Å)/Co_(90)Fe_(10)(35 Å)/NiO(800 Å) was 6.3 % and about 0.5(%/Oe), respectively. The MR ratio had 5.3 % below an annealing temperature of 200℃ which slowly decreased to 3 % above 300℃. The large blocking temperature of the spin-valve film was taken (as being) due to the good stability of the NiO films. Thus, the spin-valve films with a free NiFe/CoFe layer clearly had a high large GMR output and showed a effective magnetic field sensitivity for a suitable spinvalve head material.