The Changing Shape of Magnetic Refrigeration: an investigation of adaptive magnetic materials

This project on theoretical modelling of magnetic refrigeration materials will involve condensed matter physics theory, high performance computing and collaboration with leading experimental groups in this area in the U.K. and USA. Recently magnetic refrigeration has emerged as a promising way for a new and environmentally friendly solid state cooling technology. Prototype magnetic fridges have been proven to be much more energy efficient than conventional fridges and can span a broad temperature range around room temperature. But most prototypes use expensive rare earth metals such as gadolinium as the refrigerant and alternatives are urgently required. Several families of promising magnetic materials have been discovered but up to now this process has been a heuristic one.

A project involving Julie Staunton and an EPSRC-funded post-doc at Warwick, Theory colleagues at STFC Daresbury and experimentalists at Imperial College, London and Ames Lab., USA is in the process of establishing an ab-initio quantum materials modeling tool to transform this process and to facilitate its application by groups working with magnetic materials. We are looking for a post-graduate research student to contribute to this work and investigate how to nanostructure a large magnetocaloric effect. To this end we will study some rare earth - transition metal heterostructures and optimise the effect. This physics which produces a strong warming effect when a magnetic field is applied has another intriguing facet. It can explain how some of the most promising materials also change their shape significantly in the presence of a magnetic field. Such magnetoplastic, 'magnetic shape memory' effects have diverse potential technological applications, such as micropumps, sonars and magnetomechanical sensors.