Fermiology and spin densities from high energy X-ray scattering

Lead Research Organisation: University of Bristol
Department Name: Physics

Abstract

Magnetism plays a fascinating role in the properties of many materials. As well as being able to create an external magnetic field that can be observed or used, magnetism can determine other properties of the material itself. In our project we will be studying materials where the underlying physics behind these magnetic properties is as yet poorly understood. We will also making accurate measurements of property known as spin polarisation, in materials that could be of use for technological development in the future. The other main aspect of our work is to perform experiments that should contribute to our understanding of superconductivity. In our project we will study a set of these materials where there is currently significant controversy surrounding the underlying electronic structure, with different results being found using different experimental techniques. Our experiments will help to resolve these problems.

In order to provide the sensitivities required, these experiments all require us to use x-rays to measure specific details of the magnetic properties. The only way to obtain x-rays of sufficient intensity and with the particular properities required, is to use a synchrotron source. There are a few of these available world-wide. The choice of synchrotron for these experiments was based on the particular experimental facilities and x-ray energy available at the SPring-8 synchrotron in Japan.
 
Description We have made some discoveries about the role played by electronic structure in some fundamental material properties.

We have contributed to some computer software that will help in interpreting future experiments. This software is freely available.
Exploitation Route The research at this stage is of quite a fundamental nature. Our results relate mainly to a better understanding of exotic properties exhibited by materials. However, there is increasing use of the X-ray scattering techniques that we have ourselves used in understanding the behaviour of technologically relevant materials (e.g. batteries). The code we developed and published could be of use here.
Sectors Electronics,Energy
 
Description Developing new technological materials can be significantly aided by having a fundamental understanding of the underlying electronic structure i.e. knowing how the electrons behave. Our research has stimulated further research in a range of areas, including some that are quite applied in nature.
First Year Of Impact 2014
Sector Aerospace, Defence and Marine,Education,Energy
 
Title Compton profile calculations within ELK 
Description Elk is an open-source code for calculating electronic structure. Our contribution, to this much larger project, was a set of routines for calculating momentum distributions and Compton profiles. 
Type Of Technology Software 
Year Produced 2014 
Open Source License? Yes  
Impact We are currently able to calculate momentum densities. Hopefully, other researchers around the world will also be able to use our contribution to help interpret their experimental data. 
URL http://elk.sourceforge.net