Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), Station 3, CH-1015 Lausanne, Switzerland.
Madrid Institute for Advanced Studies, IMDEA Nanoscience, Calle Faraday 9, Campus Cantoblanco, E-28049 Madrid, Spain.
Phys Rev Lett. 2015 Mar 13;114(10):106807. doi: 10.1103/PhysRevLett.114.106807. Epub 2015 Mar 11.
We investigate the effect of H adsorption on the magnetic properties of individual Co atoms on Pt(111) with scanning tunneling microscopy. For pristine Co atoms, we detect no inelastic features in the tunnel spectra. Conversely, CoH and CoH2 show a number of low-energy vibrational features in their differential conductance identified by isotope substitution. Only the fcc-adsorbed species present conductance steps of magnetic origin, with a field splitting identifying their effective spin as Seff=2 for CoH and 3/2 for CoH2. The exposure to H2 and desorption through tunnel electrons allow the reversible control of the spin in half-integer steps. Because of the presence of the surface, the hydrogen-induced spin increase is opposite to the spin sequence of CoHn molecules in the gas phase.
我们使用扫描隧道显微镜研究了 H 原子吸附对 Pt(111)表面单个 Co 原子磁性质的影响。对于原始的 Co 原子，我们在隧道谱中没有检测到非弹性特征。相反，CoH 和 CoH2 在其微分电导中显示出许多由同位素取代确定的低能振动特征。只有 fcc 吸附物种具有磁起源的电导台阶，磁场分裂确定它们的有效自旋为 CoH 的 Seff=2 和 CoH2 的 3/2。通过隧道电子的 H2 暴露和脱附允许自旋以半整数步长进行可逆控制。由于表面的存在，氢诱导的自旋增加与气相中 CoHn 分子的自旋序列相反。
