EFFECTS OF SURFACE INTERFACE MORPHOLOGY ON GIANT MAGNETORESISTANCE AND MAGNETIC-FIELD SENSITIVITY OF NIO-BASED SPIN-VALVES/

The effects of surface/interface morphology on the giant magnetoresist ance (GMR) and magnetic field sensitivity (MFS) of NiFe/Co/Cu/Co/NiFe/ NiO/Si and Co/Cu/Co/NiO/Si bottom spin-valve films were studied. The N iO-based spin valves were fabricated on NiO films with different surfa ce roughnesses, A GMR of 4.02% and a MFS of 0.83%/Oe were obtained fro m the spin-valves with a smoother surface/interface. A GMR of 5.46% an d a MFS of 0.22%/Oe in low field and a GMR of 6.26% and a MFS of 0.16% /Oe in high field were obtained from the spin-valve films with a rough er surface/interface. It was found that the smoother the surface of th e spin-valve films, the smaller the GMR hut the larger the MFS. On the other hand, the rougher the surface of the spin-valve films, the larg er the GMR but the smaller the MFS. The mechanism for surface/interfac e morphology affecting the GMR and MFS is also explored.