Ferromagnetism in epitaxial fcc Co films on Si(111)7x7 with Cu buffer layer

The magnetic properties of ultrathin epitaxial face-centered cubic (fcc) Co(111) films on Si(111)7x7 substrates with Cu buffer layer were studied experimentally and using simulation by Monte-Carlo (MC) method in frame of the ferromagnetic Ising model. For MC simulations morphology of real film acquired from images of the scanning tunnel microscopy images was used. The conditions of experimentally observed concentration phase transitions into ferromagnetic state were compared with theoretical estimations. The nature of magnetic hysteresis and temperature dependence of magnetization is discussed.