Progressive magnetic softening of ferromagnetic layers in multilayer   ferromagnet-nonmagnet systems and the role of granularity
  We report a study of the structural and magnetic behavior of the topmost magnetic layer in a ferromagnet-nonmagnet (Co-Au) multilayer system. Glancing angle X-ray diffraction measurements performed on a series of multilayers showed a gradually increasing degree of amorphization of the topmost magnetic layer with increasing number of bilayers. Concurrently, the magnetic hardness and magneto-crystalline anisotropy of the top Co layer were found to decrease, as observed by magneto-optical Kerr effect measurements. This magnetic softening has been discussed in the light of Herzer's random anisotropy model. Micromagnetic simulations of the multilayer system also corroborated these observations. 
Siddharth S. Sahu, Vantari Siva, Paresh C. Pradhan, Maheswar Nayak,   Kartik Senapati, and Pratap K. Sahoo
cond-mat.mtrl-sci