A Novel Temperature-Induced Magnetization Transition in Pt/Co/Pt   Sandwiches
  It is found in the Pt/Co/Pt(111) sandwiches that perpendicular magnetic anisotropy weakens associated with the dramatic magnetization enhancement as the temperature decreases below a critical temperature, T_cri, which increases with the Pt overlayer thickness t_Pt. For the sandwich with enough thick Pt overlayer, it trends to an unusual state with weak perpendicular magnetic anisotropy in the absence of obvious easy direction behavior at low temperature. It suggests that Pt is more significantly polarized in the film with thicker Pt overlayer. The results reveal the strong influence of both thick nonmagnetic coverage and temperature on the electronic structure of the Pt/Co/Pt(111) sandwich. 
Weiwei Lin and Hai Sang