Implementation of a commercial medical detector for synchrotron based total scattering experiments

This project aims to develop a technique to study the local structure of complex materials. By using x-rays from a very strong X-ray source in Grenoble (a synchrotron), we obtain information on how the atoms are arranged inside the materials. Generally, studies of materials with X-rays only give information about the average position of the atoms through the distance between lattice planes given by Bragg diffraction. This project also utilizes the part of the diffractogram that does not satisfy the Bragg criterion of constructive interference. Thus, the local disorder can be studied in great detail, which is important for a variety of materials and applications. In thermoelectric materials the local disorder is of great importance, since this can reduce the thermal conductivity and thus increase efficiency. Such materials can be used to generate electricity from heat without the need for moving parts or working fluids. This project uses thermoelectric materials as model materials - this provides very useful information about the local structure of materials that can be compared with how well the material performs. The work is done in close cooperation with other projects focusing on thermoelectricity.

Total scattering methods can give access to the pair distribution function, which gives detailed information about local disorder and nanostructures. This project is aimed at developing necessary tools for the implementation of a new detector at the total scattering setup at SNBL. This will be done in close collaboration with the team at SNBL. The ambition is to facilitate total scattering methods for the Norwegian materials science community. The techniques will be tested on thermoelectric materials, wh ere disorder and nanosized features play a crucial role. In situ-measurements will be performed to assess the relationship between temperature, local order, and transport properties of the thermoelectric materials. Since such methods have been of very lit tle use in the thermoelectric society, it can be expected that new and important insight will be obtained.