Sara Elias, a young researcher from Lisbon, recently worked on the XRD characterization of an equimolar Li-Sn alloy by performing a comparative study of two solutions for sample degradation protection.
Lithium-tin (Li-Sn) alloys are potential candidates for plasma-facing components of nuclear fusion reactors. Mechano-synthesis, by means of high-energy ball milling, has proven to be an effective solution for the synthesis of prototype alloys. However, the reaction path characterization faces some challenges such as fast sample degradation when handled and exposed to air. This effect is due to lithium reaction with air (O2, H2O, and CO2) and diffusion. Two possible solutions to mitigate sample degradation during XRD analysis were investigated: a liquid paraffin coating and an airtight sample holder with a controlled atmosphere.
Not only does this work apply to the study of Li-Sn alloys, but also to work being carried out on batteries where Li-based compounds have become the de facto standard.
This research was conducted using the D8 ADVANCE diffractometer with an airtight specimen holder. Read more.
For thin films, and down to ultra-thin films (<10 nm), the accessible diffraction volume is so limited that symmetric diffraction geometries (e.g. Bragg-Brentano) have reached their limits in providing useable data, due to a penetration depth of X-ray greatly exceeding the film thickness.
Grazing incidence diffraction techniques become more appropriate and enable the enhancement of the signal through the control of the penetration depth. The confinement of the material to thin or ultra-thin films leads to highly anisotropic properties and favors the development of preferred orientation, residual stress, microstrain, or anisotropic crystallite size. Coplanar and non-coplanar grazing incidence geometries probe film properties in different directions and therefore provide complementary information for a better understanding of the film structure.
Single crystal structure determination from samples containing a certain amount of heavy elements can severely suffer from absorption effects. This holds even for investigations using relatively hard Mo-Kα radiation. Still harder radiation is now readily available from modern sources, such as Ag-Kα from the IµS 3.0, the IµS DIAMOND or In-Kα from a METALJET D2 PLUS. Harder radiation not only addresses absorption issues, but also provides several further benefits like better sample transmission, higher maximum resolution, and a very straight forward data reduction. These properties render particularly Ag-Kα radiation ideal for advanced diffraction applications like charge density or high-pressure pressure studies or material science investigations on heavily absorbing samples in general.
However, the benefit gained from the high energy radiation can be ironed out or even turned into the contrary if not properly reflected by the detector properties. With the PHOTON III HE, a photon-counting detector is available, which perfectly matches the properties of hard X-ray radiation, yielding an unparalleled high quantum efficiency also for Ag- and In-radiation.
Elite Scientific, our channel partner in Iraq, recently made the most of a heavy snowstorm to spend extra time training and testing a variety of samples with our customers, Razga, a company that conducts QC testing on imported goods. “S2 PUMA is one of the best instruments for elemental analysis, suitable for different types of applications, such as food, polymers, geological samples, glass, ceramics, etc. We received a very good system installation and training from the Elite Scientific and Bruker teams. We learned that the software is powerful and easy to use, with excellent results from liquid, solid and powder samples.” – Khallat Jamal and Danyar Mohammed, Razga Chemical Lab Assistant and Manager.
We are happy to hear that our products play a key role in ensuring the safety of consumers in Iraq. Congratulations to the team in Razga and Team Elite Scientific + Bruker AXS will continue to do our best!