Magnetic phase transition in a two-dimensional system:p(1×1)-Ni on Cu(111)

The magnetic phase transition of ultrathin epitaxial Ni films on Cu(111) is studied using the magneto-optic Kerr effect. Analysis of the thickness and temperature dependence of the spontaneous magnetization yields a shift exponent {λ}=1.44±{}0.2, in good agreement with previous experimental studies of thin Ni layers, and a critical exponent {β}=0.24±{}0.07 in good agreement with a recent study of p(1×{}1)-Fe on Au(100). In-plane symmetry does not appear to play an important role in critical behavior of these systems.