Interlayer Coupling of Co/NM/FM(NiFe and Co) Nano-Sandwich Films

Cu/Co, Cu/NiFe, Ta/NiFe bilayers and Co/Cu/Co, Co/Cu/NiFe, Co/Ta/NiFe sandwich films were deposited by a magnetron sputtering method. Magnetic properties were evaluated by VSM and spin valve magnet oresistance was investigated by a four-probe method to study the interlayer coupling of the two magnetic layers. It has been found that the interlayer coupling depended not only on the layer thickness of the nonmagnetic spacer but also on the nature of the spacer. The interlayer coupling was reduced as the spacer layer thickness increased. The result was consistent with those from observations of the magnetic domain for the trilayers by means of Lorentz Electron Microscope. The trilayers with Cu spacer layer have shown a stronger coupling than those with Ta spacer layer.