Periodic Reporting for period 3 - AtoFun (Atomic Scale Defects: Structure and Function)
Reporting period: 2020-03-01 to 2021-08-31
Transmission electron microscopy revolutionised the study of atomic scale defects by enabling their direct imaging. The novel coherent X-ray diffraction techniques developed in this project promise a similar advancement, making it possible to probe the strain fields that govern defect interactions in 3D with high spatial resolution (<10 nm). They will allow us to clarify the effect of impurities and retained gas on dislocation strain fields, shedding light on opportunities to engineer dislocation properties. The exceptional strain sensitivity of coherent diffraction will enable us to explore the fundamental mechanisms governing the behaviour of ion-implantation-induced point defects that are invisible to TEM. While we concentrate on dislocations and point defects, the new techniques will apply to all crystalline materials where defects are important. Our characterisation of defect structure will be combined with laser transient grating measurements of thermal transport changes due to specific defect populations. This unique multifaceted perspective of defect behaviour will transform our ability to devise modelling approaches linking defect structure to material function.
A deep, fundamental understanding of atomic scale defects and their effect on material function is an essential prerequisite for exploiting and engineering defects to enhance material properties for next generation power generation, energy storage and transport applications.
In parallel we have developed a new laser transient grating setup that allows high accuracy measurement of elastic properties and thermal transport at the micro- and nano-scale. Initial validation experiments have shown excellent performance of the setup and we are now looking forward to using it to examine the changes caused by crystal defects.