Pulsed Magnetic fields

Workpackage 6: Intermittently C. Strohm and M. v. Zimmermann (DESY)

The aim of the pulsed magnetic field setup is to stabilize new states of matter that are otherwise not accessible. In the focus are primarily correlated electron systems where spin, orbital, charge and lattice degrees of freedom act on similar energy scales and lead to competing ground states. One of these so far unknown phases is the state of high-Tc superconductors above the critical magnetic field, when the superconducting property has collapsed. Other systems of current interest are frustrated magnets on triangular lattices that show rich phase diagrams at high magnetic fields and materials showing topological order.

The pulsed magnetic field setup of the HIBEF project enables a detailed view onto these new stated of matter on the atomic scale. The beam from the European XFEL allows to determine the relevant degrees of freedom within the time duration of a magnet pulse. This will be achieved by the combination of various x-ray techniques with pulsed magnetic fields, including diffraction, where it is foreseen to enhance magnetic contrast at absorption edges and to employ the coherence and time structure of the XFEL to determine spatial and temporal fluctuations. The combination with absorption spectroscopy techniques like XMCD gives element sensitive ferromagnetic contrast.
The instrumentation foreseen within the HIBEF project to generate these high magnetic fields comprises a 1 MJ capacitor bank, a set of magnet coils for fields up to 60 T and for various scattering geometries. Cryosystems to cool the samples to low temperatures and a diffractometer for positioning the magnet, sample and detector system. Furthermore, a phase retarder and polarization analyzer to control the polarization of the incident and scattered X-rays.

The consortium includes partners from HLD Dresden, TU Dresden, Uni Zuerich, ESRF and DESY.