| Issue |
J. Phys. Colloques
Volume 47, Number C2, Mars 1986
32 nd International Field Emission Symposium / 32ème Symposium International d'Emission de Champ
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| Page(s) | C2-365 - C2-370 | |
| DOI | https://doi.org/10.1051/jphyscol:1986256 | |
J. Phys. Colloques 47 (1986) C2-365-C2-370
DOI: 10.1051/jphyscol:1986256
AN ATOM-PROBE STUDY OF MOLYBDENUM-CARBON REACTION
Y. ISHIKAWA, K. TAKAHASHI et T. YOSHIMURAMechanical Engineering Research Laboratory, Hitachi Ltd., Kandatsu, Tsuchiura-shi 300, Japan
Abstract
An energy focusing TOF atom-probe was constructed, which is capable of detecting 50 ions per atomic layer at intermediate evaporation voltage. The mass resolution Δm/m is 1/800 at half peak height for the Mo (110) plane and each of the detected Mo ions is clearly discriminated corresponding to each Mo isotope. This atom probe was utilized to study the reaction between molybdenum and carbon. Carbon was deposited onto a Mo tip and the tip was heated up to 800°C in various atmospheres. Migration and precipitation of carbon into the Mo (110) plane were monitored by the FIM and analyzed atomic layer by layer by the atom probe. Carbon atoms were found to migrate on the clean Mo (110) plane by heating at 600°C in a vacuum of 10-7 Pa and to precipitate into Mo. This migration was restrained by the presence of nitrogen or oxygen at a pressure of 10-4 Pa at 600°C. An atmosphere of nitrogen appears to exhibit more pronounced effect on preventing carbon migration than oxygen.