Electronic states and magnetism of monatomic Co and Cu wires

The electronic structure of monatomic Cu and Co wires:grown by step decorat ion of the vicinal Pt(997) Surface has been investigated by angle-resolved photoemission with synchrotron radiation. Sensitivity to the small amount ( approximate to 0.1 monolayer) of deposited material that forms,the: one-dim ensional wires could be achieved at photon energies close to the Pt 5d Coop er minimum, where the:photoemission cross section of the substrate valence band is strongly reduced. A single photoemission feature is associated with the 3d emission from the Cu monatomic wire. A double-peaked 3d structure i s instead observed for Co,wires, suggesting the presence of a one-dimension al exchange-split band and of local magnetic moments.