长期暴露于大气的多晶镍样品,经700℃2小时真空退火及常温和500℃暴露氧20—60L后,发现其表面将产生两种电子诱导脱附(ESD)氧正离子。所对应的电子能量阈值分别为29eV和23eV。我们认为,两种氧正离子的产生机制为俄歇诱导脱附。29eV阈能者对应于镍表面化学吸附氧的2s能级电子向真空中电离;而23eV阈能者则对应于表面层中未与镍化合的自由氧的2s电子向体内费密能级跃迁。 Long-term exposure to the atmosphere of polycrystalline nickel samples, after 700 ℃ 2 hours vacuum annealing and normal temperature and 500 ℃ exposure to oxygen 20-60L, it was found that the surface will produce two electron-induced desorption (ESD) oxygen positive ions. The corresponding electronic energy thresholds are 29 eV and 23 eV, respectively. In our opinion, the mechanism of the two oxygen ions is Auger-induced desorption. 29eV threshold energy corresponding to the nickel surface chemisorption oxygen 2s level electron ionization into the vacuum; and 23eV threshold energy corresponding to the surface layer of 2n electrons that are not combined with nickel and oxygen to the body Fermi level transition.