"Magnetostriction" is the phenomenon where a material changes its shape as a result of applying a magnetic field. It provides a mechanism of converting between mechanical and electromagnetic energy, so can be used to construct sensors. All magnetic materials exhibit magnetostriction to some extent, with James Joule noticing it in iron in 1842, but relatively few materials undergo sufficiently large magnetostrictions to be commercially useful. From a more fundamental point of view, magnetostriction draws together the solid-state physics topics of magnetism, elasticity and lattice vibrations. Understanding the interplay between structure and magnetism is in fact important in a number of research fields, such as in spintronics and magnetic cooling.
In this DPhil project, we will use computational modelling to understand what makes a good magnetostrictive material, and then use this information to identify new materials which might have superior magnetostrictive properties. The computational modelling will be performed within the framework of density-functional theory, employing supercomputers and using recently-developed techniques to calculate the magnetostriction. Depending on the interests of the student, the project could involve methodological development and adopting data-driven approaches to finding new materials. This project is suitable for a student with a materials or physics background interested in computational modelling.