Research Associate/Assistants
We currently have no vacancies for post-docs.
PhD Students
The group is always looking for highly qualified and motivated students who are interested in completing a PhD in the group. A selection of potential PhD projects is listed below, for further information on individual projects contact the academic listed. Prospective gradate students in Cambridge must apply through the University graduate admissions website, to the Department of Engineering's graduate school naming the supervisor with which you would like to work. Information on funding for prospective students in available here.
Transport Properties of Bulk Superconductors
The key parameter determining the performance of bulk superconducting materials in applications is the superconducting critical current. In modern materials this can approach 105 A/cm2 making direct transport measurements highly challenging. Consequently most characterisation of these materials relies on indirect magnetic measurements. These have the disadvantage that it is difficult to study the critical current of individual features within the superconductor, such as grain boundaries, facet lines and areas of varying pinning density. It is also difficult to study the critical current anisotropy which can be a powerful tool for understanding the nature of the flux line lattice in superconductors.
This project will build on work carried out by a current PhD student in the group who has developed a practical and low cost way of making samples of bulk superconductor with a cross sectional area small enough to permit practical transport measurements. The project will combine several experimental areas including sample preparation, sample growth, programming in LabVIEW or Python, constructing measurement probes and electrical measurements. The project would suit a physics/chemistry/materials science or engineering graduate who wishes to complete a strongly experimentally base PhD.
Bulk superconductor electric machine design
Large, single-grain (RE)BCO (where RE = rare earth element or Yttrium) bulk superconductors have significant potential to trap large magnetic fields over 17 T at temperatures below 30 K and up to 3 T at the technologically important temperature of 77 K. Such materials fabricated into disc shapes are typical candidates to replace permanent magnets in a number of large-scale applications, including electric machines, magnetic bearings and magnetic separation. In electric machines, in particular, increasing the current and/or magnetic flux density increases the power density, which leads to reductions in both size and weight of the machine. Our group is currently investigating the use of high temperature superconductors in wire and bulk form in order to increase the electrical and magnetic loading of an axial gap, trapped flux-type superconducting electric machine. A vacancy exists for a PhD student to assist in the design optimisation and building of a prototype design of such a superconducting electric machine. A major component of this research is the development of an in-situ magnetisation technique for magnetising the bulk superconductors in such a machine.
Growth and superconducting properties of (RE)Ba2Cu3O7-d single grain superconductors containing nano-size dopants
Melt processed, single grain (RE)-Ba-Cu-O bulk superconductors, where RE is a rare earth element such as Nd, Sm, Eu, Gd and Y etc., are known to be able to generate high magnetic fields due to their particularly high critical current densities, Jc's, and high irreversibility fields. As a result, these materials have high potential for practical applications. However, Jc is a structure-sensitive parameter and therefore strongly dependent on microstructure and hence processing route. Most applications of superconductors require large Jc values of order 105A/cm2 so that one must develop processing techniques that can produce superconducting materials with sufficiently large Jc in the form of practical final product geometries. Nano-size dopants are reported to increase Jc. It is not trivial to fabricate single grains of (RE)BCO due to the complexity of the growth process, especially when certain amount of dopants are purposely added for improving the superconducting properties and mechanical properties.
This project aims to reliably grow single grain bulk sample containing nano-size dopants for improving the superconducting properties. The project covers several experimental areas including powder preparation, sample growth and measurements of superconducting properties and analysis of microsturctures. The project would suit a physics/chemistry/materials/ science or engineering graduate who wishes to complete a PhD in the field of bulk superconducting materials.
