A technique for preparing tips with a radius of a few nanometers from tungsten wire is investigated. The sharp shape is obtained by electrochemical etching; further tip processing and characterization is done in ultra-high vacuum. Tips are cleaned through a high temperature annealing process and their sharpness can be quickly estimated from their field emission behaviour. Sufficiently sharp tips are imaged with a field ion microscope; full atomic characterization of the tip apex can be obtained from an analysis of the resulting images and field evaporation can be used to atomically engineer the tip apex into a desired configuration. Starting from single crystal, (111) oriented tungsten wire, a sharp tip terminating in three atoms can be fabricated; due to its geometry and its stability, this apex configuration is well suited for applications as an atomically defined electrical contact in a single molecule conductivity experiment.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.80323 |
| Date | January 2004 |
| Creators | Lucier, Anne-Sophie |
| Contributors | Grutter, P. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002095292, proquestno: AAIMQ98692, Theses scanned by UMI/ProQuest. |
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