Welcome to the Scanning Tunneling Microscopy (STM ) Laboratory. As our name implies, we use Ultra-High Vacuum (UHV) STM to study the atomic and electronic structure of carbon-based materials, such as carbon nanotubes and diamond films. Our other UHV techniques include:
- Low-Energy Electron Diffraction (LEED),
- Auger Spectroscopy, and
- Temperature Programmed Desorption.
We also have several ambient environment equipment in our lab, including:
- Raman Spectroscopy,
- air STM, and
- Atomic Force Microscopy (AFM).
We are currently investigating the field emission properties of carbon nanotubes and diamond films, and the etching & growth of epitaxial diamond films at the atomic scale. Our goal is to develop carbon films for flat panel display applications, and to understand the diamond etching and growth mechanisms at the atomic scale, which are presently unknown.
The Scanning Tunneling Microscopy and Chemical Vapor Deposition Laboratory
This is a 360º view of our lab, taken in 2001 (Click here to see an image from 1998). To establish a bearing, the camera is standing at the west wall looking east. In the left (north-east) corner is our Raman spectroscopy equipment. The long "red box" is our Argon-ion laser while the larger "white coffin" is the spectrometer.
Moving along to the next (south-east) corner, with the vent hood, is our Checmical Vapor Deposition (CVD) system. It is equipped with a variety of gas sources, controlled by needle valves and flow meters. A tube furnace, capable of reaching 1100 ºC, is also attached to this system. Here, we are able to grow our own diamond films and carbon nanotubes.
Our UHV STM system is in the next (south-west) corner. Another CVD system is attached to the STM through a linear translator so that samples can be transferred for study in the STM without subjecting them to atmospheric contamination. The main STM chamber includes a residual gas analyzer (RGA) an leak valves for precise measurement and control of input gases, and a heating stage for sample preparation. Also connected to the main STM chamber through a linear translator is a second chamber which houses a Low-Energy Electron Diffraction (LEED) detector and an Auger spectroscopy system. With this setup, we are able to grow, clean and study samples (using STM, LEED or Auger spectroscopy) while maintaining them within a UHV environment.
We have recently expanded our lab into a second room in order to ease some of the congestion in our current lab. The image to the right shows the new lab in the early stages of our transition. We've installed a 12' x 5' optical table supported by pneumatic isolation supports and added an AFM (Atomic Force Microscope) to our research arsenal. Check back soon to see our further progress.
Thin Film Deposition and Laser Laboratory
Contact Us:
University of North Texas
Department of Physics, STM Laboratory, SRB282
Denton, Texas 76203
Telephone: 940-565-4708
Fax: 940-565-4824