Ferromagnetic Order at (100)p(1×1)Surfaces of Bulk Paramagnetic Vanadium

Electron-capture spectroscopy has been used to investigate magnetic order at the topmost atomic layer of atomically clean and flat (100) surfaces of bulk paramagnetic vanadium. From low-energy electron-diffraction measurements, we find a $p(1\mathrm{}\times 1)$ surface structure. At 300 K, the long-ranged electron-spin polarization amounts to ∼34%, clearly demonstrating the existence of ferromagnetic order at the V(100) $p(1\mathrm{}\times 1)$ surface. With increasing temperature, the electron-spin polarization decreases almost linearly and disappears at a surface Curie temperature $T_{\mathrm{C}s}\approx 540$ K.