Spectroscopy at CHESS

Spectroscopy’ is defined as the branch of science concerned with the investigation and measurement of spectra produced when matter interacts with or emits electromagnetic radiation.

CHESS users apply spectroscopy to provide information on the chemical systems and electronic environment of specific elements within a sample.

How it works:

There are different types of spectroscopy, and all are useful methods to gain insight into the materials used in our environment.

When a sample is hit with X-Rays, the energy is either scattered or absorbed into the sample. Researchers can measure this energy to reveal quantitative and chemical state information about chemical bonds and the molecular structure of samples. This technique paves the way for more efficient fuel cells, the studying of ancient artifacts, and the design of healthier plants.

X-Ray Absorption Spectroscopy (XAS)

This method allows researchers to determine the electronic and molecular structure of a material. As different elements have different absorption thresholds, much information is gained by measuring the absorption of energy (X-Rays) into the sample.

This method gives insight into the geometry of atoms within a sample, a sample’s oxidation state, and length of chemical bonds.

Beamlines: PIPOXS

Applications: Crop Development - Catalysts - Energy Materials

X-Ray Emission Spectroscopy (XES)

X-ray emission spectroscopy (XES) is a powerful technique which involves exciting electrons from their shell and measuring the resulting emitted photons that occur when new electrons fill the vacancy. This method can reveal detailed electronic properties of materials, quantify bonded ligands, and reveal the spin state of atoms.

Beamlines: PIPOXS -

Applications: Catalysts - Energy Materials

X-ray Fluorescence (XRF)

XRF is a common laboratory technique for determining the relative amounts of different elements present in a sample. An elemental map of a sample can be created by focusing an X-Ray beam down to a very small spot and measuring the resulting pattern given off by the sample. These maps are extremely useful for revealing the distribution of elements in a sample.

Beamlines: PIPOXS -

Applications: Crop Development - Art & Archaeology - Mining

Unique features of spectroscopy at PIPOXS

The beamline’s flexibility comes from a range of built-in factors. The first is the energy range available at PIPOXS, which allows nearly the entire periodic table, from calcium to uranium, to be reached. Researchers can bring a variety of sample environments to be studied at the beamline as well. Users have brought liquids in solution, electrochemical cells with applied voltage, and samples frozen at 10 K. In addition, the beam at PIPOXS can be tuned with a wide beam for a large sample, down to about 100 by 200 microns for a very small sample.

Another built-in feature of PIPOXS is the spectrometers that are available, some of which are unique to CHESS. The spectrometers at PIPOXS allow both emission and absorption spectroscopy, but also allow for the combination of the two techniques into complicated 2-dimensional methods, allowing researchers to answer a range of chemical questions.