Effect of Ag buffer layer to ultrathin Co films on Si(111) surface

The magnetic properties of ultrathin Co/Ag/Si(111) films were studied by su rface magneto-optic Kerr effect. A magnetic phase diagram for binary-metal Co/Ag films deposited on Si(111) surfaces has been successfully established . The phase diagram can be divided into four regions: nonferromagnetic Co-S i compound; low Curie temperature Co film; canted out-of-plane anisotropy; in-plane anisotropy. The ferromagnetic inactive layers at the Co/Si interfa ce are formed due to intermixing of Co and Si; and can be efficiently reduc ed by the Ag buffer layer. We have demonstrated that the inactive layer thi ckness is reduced from 2.1ML for Co/Si(111), to 1.0 for Co/2.8MLAg/Si(111), and 0.0 for Co/5.6MLAg/Si(111).