Author/Authors :
Guo، نويسنده , , Donghui and Nakagawa، نويسنده , , Yuta and Ariga، نويسنده , , Hiroko and Suzuki، نويسنده , , Shushi and Kinoshita، نويسنده , , Kumiko and Miyamoto، نويسنده , , Takeshi and Takakusagi، نويسنده , , Satoru and Asakura، نويسنده , , Kiyotaka and Otani، نويسنده , , Shigeki and Oyama، نويسنده , , S.Ted، نويسنده ,
Abstract :
The surface structure of Ni2P (101̅0), a model for highly active hydrodesulfurization catalysts, was studied using scanning tunneling microscopy (STM) and low energy electron diffraction (LEED) in order to understand the reconstruction of the surface layers. Annealing at 573 K revealed a (1 × 1) LEED pattern which changed to a c(2 × 4) arrangement by further heating to 723 K. Atomic scale STM images were obtained for both the (1 × 1) and c(2 × 4) structures. Bright spots observed in the STM images were interpreted to be due to surface phosphorus atoms and this was supported by a density functional theory (DFT) simulation. Several possible models for the c(2 × 4) reconstructed structures were proposed including a P-dimer defect model, a missing-row model and a missing-row + added-row model. The last model gave the best explanation for the c(2 × 4)structure. The mechanism for the c(2 × 4) reconstruction on the Ni2P (101̅0) surface is discussed.
Keywords :
Density functional calculations , Surface relaxation and reconstruction , Nickel phosphide , Scanning tunneling microscopy , Low index single crystal surfaces
