ICP Laboratory X-Ray Fluorescence Laboratory Surface Analysis Laboratory X-Ray Diffraction Laboratory

SAL Laboratory: Room G61/G63 Chemical Sciences Bldg F10 University of NSW Kensington NSW 2052 Dr. Bill Gong: Tel: +61 (2) 9385 4694 Email:  b.gong@unsw.edu.au

Surface analysis using x-ray photoelectron spectroscopy (XPS) involves the determination of the chemical distribution and structural composition of the outermost layers of solid surfaces. In particular, surface analysis is a sensitive method of performing chemical analysis on very small quantities of material in the first 5-10 atomic layers of the solid surface. Surface analytical techniques are also capable of measuring variations in composition with depth. The nature of the surface layers control many technologically important processes including corrosion, catalysis, adhesion, friction and wear; moreover, surface layers influence the properties of a wide range of materials such as metals, ceramics, polymers, composites, alloys, textiles, biomaterials and glass.

Note that the preferred sample dimensions for our XPS instrument are length/width < 10mm and height of 1mm (maximum height 5mm).

Materials characterisation through surface analysis provides unique information about the composition of the uppermost atomic layers of solid materials, in may cases in a non-destructive manner. In addition to providing spatial (3D) elemental and chemical images at or near the surface, surface analysis can answer questions concerning the identification and concentration of surface species and the actual special distribution can be examined.

Virtually all vacuum-compatible solid materials including fibres and powder and any species deposited onto a solid surface can be analysed by XPS. Minimal sample preparation is required.

Applications:

• Surface treatments - surface modification of wool fibre
• Film technology - breakdown and depth profiles of protective films
• Metallurgy - stress corrosion cracking
• Adhesives - quality control of production processes
• Industrial catalysis ? identification of catalyst poisons
• Coatings ? thickness and composition
• Microelectronics ? impurity and dopant studies
• Biomaterials ? surface roughness
• Mining - mineral composition and surface treatments
• Polymers - chemical state of surface bonds

The Surface Analysis Laboratory uses state-of-the-art scientific techniques including:

• X-ray Photoelectron Spectrometry (XPS) with elemental mapping capability and He UV Source (UPS).
• XPS with atomic-scale ion beam etching to create elemental depth profiles of thin-films.
• High resolution XPS of organic material on surfaces to determine carbon oxidation states
• Auger Electron Microscopy and Scanning Auger Electron Microscopy (AES/SAM) for high-resolution elemental imaging of conducting samples.
• Impedance Spectroscopy for characterising the structure and electrical nature of thin films and surfaces.

Users can access the Inphaze Impedance Spectrometer by completing the registration form. In select circumstances it may be possible for a researcher to undergo training to operate the XPS. Training should be discussed with Bill Gong, and the Registration Form completed.