X-ray microscopes break the nanometre barrier

A new X-ray microscopy technique will enable scientists to view materials less than a nanometre in size. The development will help scientists visualise reactions at surfaces, such as corrosion and catalytic reactions, in real-time.

A new X-ray microscopy technique will enable scientists to view materials less than a nanometre in size. The development will help scientists visualise reactions at surfaces, such as corrosion and catalytic reactions, in real-time.

Researchers at the Argonne National Laboratory, Illinois, in collaboration with Xradia, a Californian company who specialise in X-ray optics and X-ray microscope systems, have combined X-ray reflection with high resolution X-ray microscopy to improve image resolution beyond that traditionally found in this type of microscope.

Argonne physicist Paul Fenter said: "The ability to see individual nanometre-scale features is an important benchmark for X-ray microscopy. Understanding interfacial reactivity is vital to many areas of science and technology, from the corrosion of metals to the transport of contaminants in the environment."

Scientists at Argonne utilised a technique employed in electron microscopes called phase contrast, to enable them to view features less than a nanometre in height. Previously it was only possible to observe objects at least 10nm in size using X-ray microscopes. That resolution is approximately 100 times worse than is possible when using electron and probe microscopy.

One of the advantages of X-ray microscopes also is that they can view matter in its natural state and in real time, a feature not offered by electron and probe microscopes. These require researchers to take a sample that can be disturbed or damaged during preparation. In particular, probe microscopy is an invasive technique where the probes proximity to the sample surface can cause both to become damaged.

Dr Fenter told LabTechnologist.com that this new, non-invasive X-ray technique will enable Argonne scientists to study mineral water interfaces, for example, how minerals dissolve. This has proved difficult previously using probe microscopy because the fierce reaction conditions caused the probe tip itself to react. The technique can also be used to look at biominerals produced in the body such as those found in kidney stones.

The ability to see smaller objects also enables scientists to easily visualise a process that can be difficult to interpret using scattering microscopy methods.

Steve Wang of Xradia said: "This technique opens up the possibility of watching these processes directly and will provide fundamentally new opportunities for understanding them."

Xradia developed the novel microscope setup with measurements taken at Argonne's Advanced Photon Source.