Surface Magnetism of Ni(100) near the Critical Region by Spin-Polarized Electron Scattering

It is shown that scattering of polarized low-energy electrons can be used to study magnetic critical behavior of well-characterized, free surfaces. For the topmost layers of the Ni(100) surface of a single-crystal magnetic circuit it is found that, in the temperature range 0.008<~1-TTC<~0.1, the magnetization decreases with the critical exponent β₁=0.825_-0.040+0.025, possibly indicating XY coupling at the Ni surface.