Numéro
J. Phys. Colloques
Volume 49, Numéro C6, Novembre 1988
35th International Field Emission Symposium / 35éme Symposium International d'Emission de Champ
Page(s) C6-55 - C6-59
DOI https://doi.org/10.1051/jphyscol:1988610
35th International Field Emission Symposium / 35éme Symposium International d'Emission de Champ

J. Phys. Colloques 49 (1988) C6-55-C6-59

DOI: 10.1051/jphyscol:1988610

FIELD ION MICROSCOPE AND ATOM-PROBE STUDIES OF SCANNING TUNNELING MICROSCOPE TIPS

O. NISHIKAWA, K. HATTORI, F. KATSUKI et M. TOMITORI

Department of Materials Science and Engineering, The Graduate School at Nagatsuta, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 227, Japan


Abstract
Tungsten and platinum-iridium alloy tips were observed by field emission and ion microscopes and were atom-probe mass analyzed to examine the tip surfaces corroded by exposure to air and by immersion into aqueous solutions. Although the A-P analysis indicates that the corroded layer is less than monoatomic thick for both W and Pt-Ir, the FEM and FIM observation indicates that exposure to air and immersion into solutions often result in the formation of a small protrusion at the tip apex. The observed sharp protrusion is highly desirable for a scanning tip of the scanning tunneling microscope and found to be more pronounced for Pt-Ir than W.