STM studies on the reconstruction of the Ni₂P (101̅0) surface

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• 作者：Donghui Guo ; Yuta Nakagawa ; Hiroko Ariga ; Shushi Suzuki ; Kumiko Kinoshita ; Takeshi Miyamoto ; Satoru Takakusagi ; Kiyotaka Asakura ; Shigeki Otani ; S.Ted Oyama
• 关键词：Nickel phosphide ; Scanning tunneling microscopy ; Surface relaxation and reconstruction ; Density functional calculations ; Low index single crystal surfaces
• 刊名：Surface Science
• 出版年：2010
• 出版时间：30 August 2010
• 年：2010
• 卷：604
• 期：17-18
• 页码：1347-1352
• 全文大小：1983 K

文摘

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.