화학공학소재연구정보센터
Thin Solid Films, Vol.681, 32-40, 2019
Uniaxial magnetic anisotropy in three-bilayer Co/Cu and Co/Al superlattices
We present the magnetic properties of three-bilayer superlattices [Co(0.8 nm)/Cu(1.1 nm)](3) and Co(0.8 nm)/Al (2.2 nm)](3) grown by magnetron sputter deposition on SiO2 substrates. Using the surface magneto-optical Kerr effect we observed longitudinal magnetic hysteresis loops with low coercivity values of < 17 x 10(-4) T and < 7 x 10(-4) T from Co/Cu and Co/Al superlattices, respectively. From the hysteresis loops as a function of in-plane azimuthal angle of the Co/Cu and Co/Al superlattices, we observed an in-plane uniaxial anisotropy in coercivity and squareness. Using a four-point square configuration we observed positive and negative anisotropic magnetoresistances (AMR) with values + 0.5% and - 0.5% from Co/Cu superlattice depending on whether the applied current is perpendicular or parallel to the applied magnetic field direction, respectively. The surface morphology including vertical root-mean-square roughness and lateral correlation length were examined by atomic force microscopy. The number of bilayers and the thicknesses of Co, Cu and Al in the superlattices were examined by X-ray reflectivity. The observed magnetic properties were correlated to the interface roughness and layer thickness. The low coercivity, low saturation field, near-one squareness, and finite MR value of the three-bilayer Co/Cu superlattice has potential applications in low magnetic field detection and sensors.