Neutrons and X-rays at high field, from superconductors to viruses


by Alexander T. Holmes, School of Physics and Astronomy, University of Birmingham, UK

With a new 17 T cryomagnet [1], designed to be used on neutron or X-ray beamlines throughout Europe, we are exploring new areas for the interaction of high magnetic fields with superconductors, magnetic materials and colloids in liquid suspension. We welcome new suggestions for collaboration, particularly when we extend our sample temperature range down to the mK region.

I shall describe the technical developments allowing SANS & SAXS at such high fields, show the possibilities of alignment of “non-magnetic” particles, and give the results of observation of quantised magnetic flux line lattices in unconventional superconductors.

It has become clear that the lattice structures and the spatial and temperature variation of the flux line magnetic fields can tell us much about the nature of the superconductivity. We shall illustrate this by measurements on cuprate [2] and pnictide [3] materials. I shall also describe the first SAXS measurement at 17 T, which has produced new revelations about charge density wave ordering in the
high temperature superconductor YBCO [4-5].

[1] AT Holmes et al., Rev. Sci. Instrum. 83, 023904 (2012).
[2] AS Cameron et al. in preparation.
[3] H Kawano-Furukawa, et al., Phys. Rev.B 84, 024507 (2011).
[4] J Chang et al. Nature Physics 8, 871–876 (2012).
[5] E Blackburn et al. Phys. Rev. Lett. 110, 137004 (2013).