Single-crystal X-ray diffraction and resonant X-ray magnetic scattering at helium-3 temperatures in high magnetic fields at beamline P09 at PETRA III
The resonant scattering and diffraction beamline P09 at PETRA III at DESY is equipped with a 14 T vertical field split-pair magnet. A helium-3 refrigerator is available that can be fitted inside the magnet's variable-temperature insert. Here the results of a series of experiments aimed at determining the beam conditions permitting operations with the He-3 insert are presented. By measuring the tetragonal-to-orthorhombic phase transition occurring at 2.1 K in the Jahn-Teller compound TmVO4, it is found that the photon flux at P09 must be attenuated down to 1.5 × 109 photons s-1 for the sample to remain at temperatures below 800 mK. Despite such a reduction of the incident flux and the subsequent use of a Cu(111) analyzer, the resonant X-ray magnetic scattering signal at the Tm LIII absorption edge associated with the spin-density wave in TmNi2B2C below 1.5 K is intense enough to permit a complete study in magnetic field and at sub-Kelvin temperatures to be carried out.
This article is published as Francoual, S., J. Strempfer, J. Warren, Y. Liu, A. Skaugen, S. Poli, J. Blume, F. Wolff-Fabris, P. C. Canfield, and T. Lograsso. "Single-crystal X-ray diffraction and resonant X-ray magnetic scattering at helium-3 temperatures in high magnetic fields at beamline P09 at PETRA III." Journal of Synchrotron Radiation 22, no. 5 (2015): 1207-1214. DOI: 10.1107/S1600577515014149. Posted with permission.