Thomas Research Group

Physical Chemistry, Surface Science, Materials Science

We work in the interdisciplinary fields of Surface Science and Materials Science. The optical, electronic, and mechanical properties of materials are investigated to determine how the CHEMISTRY of the formation processes affects the PHYSICS of the final product. Below are a number of projects which we have worked on, which we are starting to work on, or which we would like to work on. We hope this gives you a flavour of our interests and activities.

Some Research Projects

• Chemical Etching of Porous Silicon
• Interfacial States in Semiconducting BaTiO₃
• Organometallic Chemical Vapour Deposition (OMCVD)
• Scanning Near-Field Optical Microscopy
• Scanning Tunneling Microscopy
• Scanning Force Microscopy
• Nanostructure Formation
• Collosal Magnetoresistance (CMR)

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Current and Former Group Members

Information concerning students, their status while in our lab, any special awards they received, their current activities, and the project they worked on while here.

Taras Kolodiazhyni M.Sc. in progress Held 2 OGS Scholarships Holds NSERC PGSB award. Scanning Tunneling Spectroscopy of PTCR BaTiO3 Jeff Broderick M.Sc. in progress Spatially Resolved Spectroscopy of Porous Silicon Lori Jones Ph.D. completed 1996 Lecturer at U. of Guelph and U. of Waterloo Thesis title: "Development of Techniques Used for the Formation and Characterization of Nanostructured Materials" John Wang Post-Doc 1994 Research Scientist with Seimens Canada Organometallic Chemical Vapour Deposition of Thin Metal Films Ömer Yükseker B.Sc. 1995 Grad Student in Chemistry at Univ. of Toronto Photochemical Etching of Porous Silicon Geoff Taylor B.Sc. 1995 Medical Student Photocontrolled Etching of Porous Silicon Karen Bach B.Sc. 1995 Grad Student in U.S. Organometallic Chemical Vapour Deposition Mike Dinel B.Sc. 1995 High Scool Teacher Thermal Desorption Studies of Organoimetallic Molecules from Si(111) Surfaces

Shawn Campbell B.Sc. 1994 Scientist in Food Industry Lab Surface Structural Features of Chemically Etched Porous Silicon Elli Nakamichi B.Sc. 1994 Forensic Scientist Chemical and Electrochemical Formation of Porous Silicon Laura Zajchowski B.Sc. 1993 NSERC UG Award Holder Grad Student Food Science Holds NSERC PGSA award Electrochemical Production of Porous Silicon and its Spectral Properties Tanya Bartlett B.Sc. 1992 NSERC UG Award Holder Grad Student Chemical Physics Design of Metal Evaporation Source for use in UHV Andrea Weiniger B.Sc. 1990 Ph.D. Grad Student in Chemical Physics XPS Studies of Bioimplants made from Titanium/Vanadium Alloys Ranjit Plaha B.Sc. 1990 Design of STM Vibration Isolation System John Wright B.Sc. 1991 Computer Network Engineer Design and Construction of Thermal Descorption Spectrometer

Here on the right is a picture of John Wright standing next to the ultrahigh vacuum chamber. John helped design and build the Thermal Desorption Spectrometer we used in a series of experiments.

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Publication List

1. D.F. Thomas and T.V. Kolodiazhnyi, "Hysteresis in the I-V tunnelling spectra of n-type BaTiO₃ Ceramics", in preparation.
2. D.F. Thomas, "Porous Silicon", invited review chapter in Handbook of Nanostructured Materials and Nanotechnology, ed. H.S. Nalwa, to be published by Academic Press, (1998).
3. D.F. Thomas, T.V. Kolodiazhnyi, and A.G. Belous, "Scanning Tunneling Microscopy of n-doped BaTiO₃ ceramics" accepted by J. Euro. Ceram. Soc., (February 1998).
4. D.F. Thomas and M.D. Baker, "Shielding in atoms and the explanation of the periodic table", submitted to J. Chem. Ed. (1997).
5. L.A. Jones, Ö. Yükseker, and D.F. Thomas, "Dependence of photochemically etched porous silcion formation on photoetching wavelength and power", J.Vac. Sci. Technol. A14, 1505 (1996).
6. L.A. Jones, G.M. Taylor, F.-X. Wei, and D.F. Thomas, "The chemical etching of silicon: smooth, rough, and glowing surfaces" Prog. Surf. Sci. 50, 283 (1995).
7. L.A. Jones, F.-X. Wei, and D.F. Thomas, "Design and implementation of a heatable, all-glass doser for sensitive organometallic compounds in an ultrahigh vacuum environment" Rev. Sci. Instrum. 66, 4981 (1995).
8. S.D. Campbell, L.A. Jones, E. Nakamichi, F.-X. Wei, L.D. Zajchowski, and D.F. Thomas, "Spectral and structural features of porous silicon prepared by chemical and electrochemical etching processes" J. Vac. Sci. Technol. B13, 1184, (1995).
9. L.A. Jones, F.-X. Wei, and D.F. Thomas, "Movable ultrahigh vacuum sample mount: heating, cooling, and temperature measurement capabilities" Rev. Sci. Instrum. 66, 1146 (1995).
10. L.A. Jones and D.F. Thomas, "Nanometer scale instability at sliding interfaces: tribological considerations in Scanning Tunneling Microscope design" J. Vac. Sci. Technol. A10, 636 (1992).
11. D.L. Blanchard, D.F. Thomas, L.R. Allen, and T. Engel, "A helium diffractometer study of surface roughening on Ni(117)" Surface Science 222, 477 (1989).
12. J.C. Polanyi, D.F. Thomas, and J.-P. Visticot, "Dynamics of non-adiabatic reactions. IV: Effect of enhanced collision energy in the four-centre reaction F₂ + Na₂ F + NaF + Na*" J. Phys. Chem. 93, 4730 (1989).
13. J.C. Polanyi, W. Reiland, C. Stanners, D.F. Thomas, and J.-P. Visticot, "Dynamics of non-adiabatic reactions. III: Effect of enhanced collision energy in F + Na₂ NaF + Na*" J. Phys. Chem. 93, 4723 (1989).
14. J.A. Barnes, M. Keil, J.C. Polanyi, W. Reiland, and D.F. Thomas, "Effect of changing reagent energy. XII: Dependence of internal state distributions on reagent translation in F + H₂ HF + H" in J. Chem. Phys.
15. J.A. Barnes, J.C. Polanyi, W. Reiland, and D.F. Thomas, "Product vibrational and rotational state distributions from the surface reaction F + H₂ HF + H" J. Chem. Phys. 82, 3824 (1985).
16. J. E. Bertie, D.F. Thomas, and W.R. Thorson, "The infrared spectrum of sodium bifluoride NaHF₂ at 295 K from 2100 to 5700 wavenumbers" J. Chem. Phys. 73, 5399 (1980).