Effect of planar doping in Co/SiO₂-Ni/Cu/Co structures

The effect of interfacial planar doping with insulating granular layer in a sandwiched structure was studied. By inserting a thin SiO₂-Ni layer into the sandwiched Co/Cu/Co structures, the magnetoresistance curve as a function of the magnetic field changed significantly because of reduction of interlayer coupling and the change of its switching mechanism of the magnetizations by the interface modification. The switching fields are 10 and 60Oe for the magnetization reversals in two magnetic layers. The MR peaks are square-shaped with the width of about 30 Oe and the peak MR ratio of 3.3%.