Monitoring the surface electronic states of crystals in vapor-phase growth processes under magnetic field

摘要

We presetn a useful techqnue to moniotr the electronic states fo the sruface aomic laeyr in magnetic fied. The system employs a filament to emit thermal electrons, a grid to cotnrl the enjergy distrbution function of incident electrons and a itanium subsrate to be investigated. The sruface electronic structure of he oxide laeyr of the titanium substrate was derived by analyzing the transmission current whcih was emasured as af uncion of magnetic field and elecron energy The resutls re expressed as contour lots of the quantititiels related to the transmission probability T in thye twodimensioanl wave number space; perpendicualr andparalell components to the surface. The surface oxidized in air at 200 deg C for 2 h conained a lot of adsorbed oxgyen atoms. The adsrobed oxgyen atoms, which showed he non-directional kelectronic strucutres, disappeared after he evacuaiton for two hours at 10~-7 Torr, and then three-dimensinal order of surface atoms appeared.