TEMPERATURE-DEPENDENCE OF FERROMAGNETISM AT NI(111) SURFACES DETERMINED WITH ELECTRON-CAPTURE SPECTROSCOPY (ECS)

Electron capture spectroscopy has been used to probe the electron spin polarization (ESP) at the topmost atomic layer at Ni(111) surfaces. Contrary to bulk behavior, the ESP-signal measuring the long-range surface magnetic order decreases from minus 43% at T equals 293 K almost linearly to zero at the bulk Curie temperature T//C//b equals 631 K. Local surface magnetic order is temperature independent and is detected far above T//C//b. Such a behavior is only found for the 3d transition metal Ni.