City Research Online

Abstract

An inelastic electron tunnelling spectrometer has been constructed incorporating novel improvements in design, resulting in improvements in resolution and reduction in background noise levels relative to previous instrumentation. In particular, the use of epoxy resin circuit board in place of glass as the junction substrate, and the careful definition of oxidation parameters has resulted in a considerable improvement in junction integrity. The utilisation of a two terminal instead of a four terminal bridge arrangement, combined with electronic circuitry specifically designed to minimise noise levels has resulted in a significant enhancement of signal to noise ratio. The design of an epoxy resin junction support of minimal thermal capacity to enable direct insertion of the junction into a cryogenic storage dewar has resulted in the maximum utilisation of refrigerants.

Infusion and liquid doping methods have been investigated, and the effects of dopant concentration and spurious contamination upon junction performance have been elucidated. High resolution tunnelling spectra have been obtained for benzaldehyde, m-bromobenzaldehyde, N-methylaniline and N(3)-benzoy1-3(1), 5(1)-diacetyl1-2(1)-bromo-2(1)-deoxyuridine: Comparison with infrared and Raman data has allowed the interpretation of molecular conformation of these molecules on the aluminium oxide surface. The inability of other molecules including water, benzene and chromium hexacarbonyl to produce satisfactory tunnelling spectra has been observed.

A survey of the present and potential applications of IETS as an analytical and spectroscopic technique has been compiled.

Publication Type:	Thesis (Doctoral)
Subjects:	Q Science > Q Science (General) Q Science > QC Physics Q Science > QD Chemistry
Departments:	School of Health & Medical Sciences > School of Health & Medical Sciences Doctoral Theses Doctoral Theses

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