X-ray spectroscopy
X-ray and UV photoelectron spectroscopy
Photoelectron (or photoemission) spectroscopy measures the binding energies in a substance, which are characteristic of the chemical structure and molecular bonding. Using either X-ray (XPS) or ultraviolet light (UPS), this is a very sensitive technique for measuring the chemical composition of surfaces. Depth profiling is possible using an ion sputter source.
This instrument, located in the Sydney Nanoscience Hub, is designed for surface and thin film characterisation. It is capable of both X-ray Photoelectron Spectroscopy (XPS) and Ultraviolet Photoelectron Spectroscopy (UPS) and provides information on elemental composition, oxidation states and electronic states.
A Thermo Scientific MAGCISTM dual mode ion beam enables depth profiling and surface cleaning using either a monatomic or gas cluster beam, while a patented dual beam flood source prevents sample charging enabling easy analysis of insulators.
The size of the x-ray beam can be adjusted from 30 – 400μm in 5μm increments and samples analysed as single points or lines. Chemical imaging is also available allowing distribution maps from 0.5 mm x 0.5 mm up to 3 mm x 3mm in size to be collected.
Specialised accessories include:
- Tilt module – for the collection of angle-dependent XPS with depth resolution of ~ 3nm
- Vacuum transfer module - enables surfaces and devices to be transferred from cleanrooms or PC labs to the instrument without exposure to surface contamination.
The SPECS EnviroESCA is a Near Ambient Pressure (NAP) system that allows the XPS experiment to be performed at up to 50 mbar pressure, significantly higher than the ultra-high vacuum of a standard XPS instrument. This is ideal for investigating the surface chemistry of catalysts, liquids and liquid-solid interfaces.
The EnviroESCA also has a heating stage allowing measurements between 0 - 600°C, can use process gases, and apply electrical current to the samples, for a range of operando measurements.
X-ray fluorescence
The elemental composition of a specimen can be determined by the characteristic radiation emitted after the sample is excited by X-rays. X-ray fluorescence (XRF) spectroscopy provides quantitative information about the elemental composition of bulk samples, or (in the case of XRF microscopy) compositional variation across samples.
Please contact Xun (Rex) Geng.
The Bruker Tracer 5i is a handheld energy-dispersive XRF spectrometer, ideally suited for analyses both in the laboratory and in the field, and capable of analysing elements from Mg to U (variously % to ppm levels). The system is equipped with an internal camera, 3mm and 8mm collimators, and an automated internal wheel filter as well as a manual filter slot. Current calibrations include those for metals, ceramics and glass, with custom calibrations possible with the use of EasyCal software.
The Bruker ARTAX800 µ-XRF system is a portable energy-dispersive XRF spectrometer, with a 70 µm resolution, capable of both spot analyses and mapping. Elements from Na to U can be analysed (variously % to ppm levels) and a rotating measuring head enables analysis of a wide variety of samples without the need for contact, including samples too large to otherwise be analysed by conventional laboratory instruments and extremely small samples that require high resolution. Custom calibrations are possible with the use of EasyCal software.
The Rigaku SuperMini200 is a benchtop X-ray fluorescence (XRF) analyser that offers high sensitivity and accuracy. The SuperMini200 is capable of analysing elements ranging from fluorine to uranium, and features wavelength dispersive optics, a high-resolution detector and easy-to-use software.
- xrFuse1 fusion furnace
This compact electric fusion machine is designed for the preparation of single glass discs for more accurate XRF measurements.
Our partners at ANSTO operate two XRF beamlines at the Australian Synchrotron (XRF and Nanoprobe), covering different X-ray energy ranges, sample conditions and spatial resolutions. We can provide advice on their suitability for your experiment and how to access them.
X-ray absorption and X-ray emission spectroscopy (XAS/XES)
X-ray absorption spectroscopy (XAS) probes how X-rays are absorbed by core electrons, revealing oxidation states and local atomic structure around selected elements. X-ray emission spectroscopy (XES) is effectively very-high energy resolution X-ray fluorescence (XRF), which can reveal oxidation state and ligand identity.
The Brimstone XES system offers high-resolution X-ray fluorescence outcomes aiming to reveal valence band dynamics and orbital environment during various electron transit process in complex. It uses an innovative optical geometry with a Pd/W X-ray tube to provide synchrotron-quality X-ray emission spectra within the 2 – 5 keV range.
The EasyXAFS300+ system is the lab-based X-ray adsorption/emission spectrometer (XAS/XES) combined system. It has 100W W/Pd and 1.2kV Mo/Ag X-ray source covering the 4.5 – 20 keV energy range, which is comparable to a typical synchrotron XES and XAS beamline. It is suitable for studying most first- and third-row transition metals and lanthanoids. In-situ/In-operando experiments are available.
This instrument is located at UNSW and is jointly operated with the Mark Wainwright Analytical Centre at UNSW.
Our partners at ANSTO operate three specialised X-ray absorption spectroscopy beamlines at the Australian Synchrotron (XAS, SXR and MEX) covering the full range of elemental absorption edges. We can provide advice on their suitability for your experiment and how to access them. Scheduled beamtime is available to all research groups in the University of Sydney.