Epitaxial growth of Se films deposited on UHV-cleaved KI irradiated by electrons

The epitaxial growth of Se deposits on UHV-cleaved KI surfaces irradiated by electrons at a dose of 1014-1018 electrons/cm2 at 250-1000 eV has been studied by transmission electron microscopy and electron diffraction. In the absence of electron irradiation, the Se deposits have a strong preferred orientation (101-bar0)Separallel(001)KI and [0001]Separallel[110] and [11-bar0]KI. With electron irradiation, the (336-bar8-bar) plane of the deposits is approximately parallel to the substrate surface, and the [1-bar100] direction of Se is parallel to the [100] and [010] of KI in addition to the above orientation. The epitaxial growth of the (336-bar8-bar) plane depends on the irradiation dose rather than on incident electron energy, and the deposition rate ranges from 0.5 to 8 A/s. The morphology of tahe Se deposits changes drastically depending on the rate of deposition and/or time of exposure to a UHV atmosphere after electron irradiation. (author)