J. Phys. Colloques
Volume 49, Numéro C6, Novembre 198835th International Field Emission Symposium / 35éme Symposium International d'Emission de Champ
|Page(s)||C6-221 - C6-226|
J. Phys. Colloques 49 (1988) C6-221-C6-226
THE INTERACTION OF GeH4 WITH W, Ni AND Ge SURFACES IN HIGH ELECTRIC FIELDSA. CISZEWSKI1, O. FRANK2 et J.H. BLOCK2
1 Institute for Experimental Physics, University of Wroclaw, Cybulskiego 36, PL-50-205 Wroclaw, Poland
2 Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-1000 Berlin 33, F.R.G.
The decomposition, and the interaction of GeH4 with the surfaces of W, Ni, Ni-Ge alloy and Ge in a high electric field, was studied for the temperature range 80-290 K, by means of field-ion appearance potential spectroscopy and field emission microscopy. The onsets of the integral energy distribution of positive ions showed that there was no surface influence on the GeH2+ formation, whereas some fraction of the GeH3+ was either formed during the GeH4 interaction with the field emitter surface or was field desorbed from the surface. The parent molecular ion, GeH4+, was detected only in the case of Ge emitters. Strong enhancement of the decomposition rate of GeH4 was observed on specific areas of Ni, which were identified as the regions where <123>, <135> and <012> poles are localized. Accumulation of the GeH4 and its decomposition products on these areas were considerably faster than the average accumulation rate. Such site specific interaction was also observed for the Ni-Ge alloy.