Surface magnetism of YCo2

Recent theoretical work [S. Khmelevskyi et al., Phys. Rev. Lett. 94 (2005) 146403] predicts for the paramagnetic compound YCo2 ferromagnetic order of the (1 1 1) surface. Here we report on results of a spin-resolved photoelectron spectroscopic (SRPES) study of YCo2 thin films grown on a W(1 1 0) substrate. While no clear spin-asymmetry was observed for bulk sensitive data taken at hν = 1253.6 eV, the surface sensitivity data obtained at hν = 21.2, eV photon energy revealed a clear spin-asymmetry probing the validity of the theoretical prediction.