Novel scanning probe microscope instrumentation with applications in nanotechnology

Humphry, Martin James (2000) Novel scanning probe microscope instrumentation with applications in nanotechnology. PhD thesis, University of Nottingham.

[img]
Preview
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (15MB) | Preview

Abstract

A versatile scanning probe microscope controller has been constructed. Its suitability for the control of a range of different scanning probe microscope heads has been demonstrated. These include an ultra high vacuum scanning tunnelling microscope, with which atomic resolution images of Si surfaces was obtained, a custom-built atomic force microscope, and a custom-built photon emission scanning tunnelling microscope. The controller has been designed specifically to facilitate data acquisition during molecular manipulation experiments.

Using the controller, the fullerene molecule C60 has been successfully manipulated on Si(100)-2x1 surfaces and detailed data has been acquired during the manipulation process. Evidence for two distinct modes of manipulation have been observed. A repulsive mode with success rates up to 90% was found to occur with tunnel gap impedances below 2GΩ, while between 2GΩ and 8GΩ attractive manipulation events were observed, with a maximum success rate of ~8%. It was also found that the step size between feedback updates had a significant effect on tip stability, and that dwell time of the STM tip at each data point had a critical effect on manipulation probability.

A multi-function scanning probe microscope head has been developed capable of operation as a scanning tunnelling microscope and an atomic force microscope in vacuum and a magnetic field of 7T. The custom-built controller also presented here was used to control the head. A three-axis inertial sliding motor was developed for the head, capable of reproducible step sizes of <1000Å. In addition, an optical fibre interferometer was constructed with a sensitivity of 0.2Å/ √Hz. Preliminary development of a magnetic resonance force microscope mode has also been performed, with initial results showing such a system to be feasible.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Beton, P.H.
Bowtell, R.W.
Keywords: Control equipment, Scanning tunneling microscopy, Manipulators, Atomic force microscopy, Scanning light microscopy, Solid state physics
Subjects: Q Science > QH Natural history. Biology > QH201 Microscopy
Faculties/Schools: UK Campuses > Faculty of Science > School of Physics and Astronomy
Item ID: 13743
Depositing User: EP, Services
Date Deposited: 06 Nov 2013 10:35
Last Modified: 15 Sep 2016 07:00
URI: http://eprints.nottingham.ac.uk/id/eprint/13743

Actions (Archive Staff Only)

Edit View Edit View