Multi-frame acquisition scheme for efficient energy-dispersive X-ray magnetic circular dichroism in pulsed high magnetic fields at the FeK-edge

Abstract

Using a fast silicon strip detector, a multi-frame acquisition scheme was implemented to perform energy-dispersive X-ray magnetic circular dichroism at the iron K-edge in pulsed high magnetic fields. The acquisition scheme makes use of the entire field pulse. The quality of the signal obtained from samples of ferrimagnetic erbium iron garnet allows for quantitative evaluation of the signal amplitude. Below the compensation point, two successive field-induced phase transitions and the reversal of the net magnetization of the iron sublattices in the intermediate phase were observed.

Microsecond time-resolved energy-dispersive EXAFS measurement and its application to film the thermolysis of (NH4)2[PtCl6]

“…A focus spot of 60 × 35 μm (horizontal × vertical) was obtained with the focusing mirror and the monochromator. The silicon ULTRA detector (Quantum Detectors, Harwell Oxford, UK) with 512 × 1 (horizontal × vertical) pixels and a pixel size of 50 μm56 was used to measure the EXAFS spectra in transmission mode. The energy resolution of our measured absorption spectrum, which is controlled by several parameters2930, is obtained to be 0.89 eV through a convolution calculation of a reference spectrum with known energy resolution, and the detailed calculations are described in the caption of Figure S6 in SI.…”

“…The upgraded control program allows to record a sequence of 7×10 7 frames continuously, producing a predefined data matrix of 72 GB. Detailed descriptions of the silicon quantum detector are given in previous reports56. A complete EXAFS spectrum with an overall energy range of 390 eV at the Pt L 3 edge could be obtained with a single exposure to the detector.…”

“…Microsecond EDE has only recently become accessible with the advent of the fast readout silicon Quantum Detectors ULTRA and the high brilliance third generation synchrotron radiation sources56. The time domain for chemically or thermally driven reactions could vary from hours to ultrafast regime when atomic or electronic motions are the dominant effect.…”

X-ray Diffraction and Absorption Spectroscopy in Pulsed High Magnetic Fields

“…54,[60][61][62][63] Of course, the evolution of pulsed-high-field X-ray experiments has been aided by continuous improvement and development in instrumentation. A high-repetition-rate (or fast-cooling) magnet 71) and a high-frame-rate array detector 9,67) are helpful for increasing effective measurable time and thus for improving data quality. Long, enduring efforts for suppressing sample vibration were necessary for obtaining data in high accuracy as well.…”

“…The combination of the use of a pulsed magnet and DXAFS method was used in the European Synchrotron Radiation Facility (ESRF) 64) in France and has been applied to X-ray magnetic circular dichroism. 66,67) X-ray absorption spectroscopy studies using DXAFS were also conducted in the Advanced Photon (AR) ring at the Photon Factory in Japan. 68,69) The disadvantage of DXAFS is that the finite beam size focused at the sample position can cause the deformation of the absorption spectrum by reflecting the inhomogeneity of the sample, especially for a powder sample; this is because beams with different photon energies pass through different sample positions if the focal spot size of the beam is not sufficiently small.…”