Magnetic Phenomena in Condense Matter - Scientific Overview

Superconductors respectively correlated electron systems exhibit spectacular properties. Since the discovery of superconductivity in the year 1911 by Heike Kamerlingh Onnes, open questions in this field of research still remain. The HIBEF user consortium focuses on material classes and phenomena, such as

• Unconventional superconductors, e.g. cuprates and iron pnictides
• Electronic liquid crystal states in superconductors
• Electronic ordering phenomena, superconductor-insulator transitions 
• Coexistence and competition of superconductivity and magnetism
• Novel high-field states (e.g. FFLO) in superconductors

To perform such research, we develop an advanced next-generation x-ray diffractometer that allows for experiments under extreme magnetic-field conditions. There is a tremendous demand in the science community for stronger magnetic fields, which can only be met by pulsed-field techniques. As a consequence of this method, time for data collection is extremely restricted and such a setup should be combined with most brilliant sources X-ray sources.

The HIBEF user consortium will provide such an experimental setup at the HED station of the European XFEL. A two stage installation is foreseen. At day-1 a double conical solenoid will be available, with an exit opening of ±30 degree for the diffracted beam. The development of a small series of test magnets has shown that magnetic fields up to 60 tesla can be reached. The pulse duration of such magnets is adapted to the European XFEL's bunch-train structure. Pulse currents up to 100 kA and pulse energies up to 750 kJ will be provided by a 24 kV capacitor bank. With such coils, single crystal as well as powder diffraction experiments, XMCD and spectroscopic measurements can be performed. In selected cases also anomalous diffraction experiments are feasible. These experiments are limited by the geometry of the coil more precisely the angular opening of the exit cone of ±30°2ϑ.

At the second stage, a split-pair coil is foreseen with a higher angular opening >> 90° in 2ϑ, this setup is dedicated for resonant experiments at lower photon energies. In such coil geometry, we aim for magnetic fields up to 45T.