Acta Phys. -Chim. Sin. ›› 2003, Vol. 19 ›› Issue (08): 686-688.doi: 10.3866/PKU.WHXB20030802

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Study of Displacement Adsorption of N2 by O2 on Surface of Polycrystalline W via Threshold Energy of Electron-stimulated Desorption

Zhang Tong;Wu Qiang;Hu An;Mao Fu-Ming;Yang Xue-Qian   

  1. Electronic Engineering Department, Southeast University, Nanjing 210096; National Laboratory of Solid State Microstructures and Physics Department, Nanjing University, Nanjing 210093; School of Mathematics & Computer Science, Nanjing Normal University, Nanjing 210097
  • Received:2002-11-25 Revised:2003-03-06 Published:2003-08-15
  • Contact: Zhang Tong E-mail:njutonnyz@sina.com

Abstract: The threshold energies of electron-stimulated desorption of N2 and O2 from polycrystalline W in vacuum (1×10-3 Pa) at T=300 K are measured. For O2-W couple, the threshold energy is about 15.5 eV; For N2-W couple, the threshold energy is about 13.8 eV. The displacement adsorption of N2 by O2 from the surface of polycrystalline W is studied using the measured threshold energy. The result shows that within a given time interval, N2 could be displaced by O2 on the surface of W, but the opposite process could not occur.

Key words: Electron-stimulated desorption, Threshold energy, Displacement,  Adsorption, Modulation