Study of [Co/Ni]N/[Co/Pt]N-based spin valves with perpendicular magnetic anisotropy

[Co/Ni]_N and [Co/Pt]_N multilayers are ideal perpendicular magnetic anisotropy materials due to their high spin polarization. There are strong perpendicular magnetic anisotropy(PMA) energy between Co and Ni or Pt layer, and if the energy is strong enough to overcome the demagnetizing effect the easy magnetization axis can be perpendicular to the film^[1-3]. Perpendicularly magnetized spin valve structure can be prepared by these properties and it has significant implication in high density magnetoresistive random access memory(MRAM) and other aspects^[4]. In this work, a perpendicularly magnetized spin valve structure was developed, consisted the ferromagnetic [Co/ Ni] and [Co/Pt] multilayers and separated by a Au spacer. The magnetoresistance(MR) of the samples with the thickness of Au and the layer repetition number of N was studied.