Resonant inelastic X-ray scattering of magnetic excitations under pressure

Resonant inelastic X-ray scattering (RIXS) is an extremely valuable tool for the study of elementary, including magnetic, excitations in matter. The latest developments of this technique have mostly been aimed at improving the energy resolution and performing polarization analysis of the scattered radiation, with a great impact on the interpretation and applicability of RIXS. Instead, this article focuses on the sample environment and presents a setup for high-pressure low-temperature RIXS measurements of low-energy excitations. The feasibility of these experiments is proved by probing the magnetic excitations of the bilayer iridate Sr3Ir2O7 at pressures up to 12 GPa.

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Montel mirror based collimating analyzer system for high-pressure resonant inelastic X-ray scattering experiments

Journal of Synchrotron Radiation ◽

10.1107/s1600577520005792 ◽

2020 ◽

Vol 27 (4) ◽

pp. 963-969

Author(s):

J.-K. Kim ◽

Diego Casa ◽

Xianrong Huang ◽

Thomas Gog ◽

B. J. Kim ◽

...

Keyword(s):

High Pressure ◽

Energy Resolution ◽

Low Energy ◽

Energy Excitation ◽

High Expectations ◽

X Ray ◽

X Ray Scattering ◽

Diamond Anvils ◽

Highly Correlated ◽

Ray Scattering

Resonant inelastic X-ray scattering (RIXS) is increasingly playing a significant role in studying highly correlated systems, especially since it was proven capable of measuring low-energy magnetic excitations. However, despite high expectations for experimental evidence of novel magnetic phases at high pressure, unequivocal low-energy spectral signatures remain obscured by extrinsic scattering from material surrounding the sample in a diamond anvil cell (DAC): pressure media, Be gasket and the diamond anvils themselves. A scattered X-ray collimation based medium-energy resolution (∼100 meV) analyzer system for a RIXS spectrometer at the Ir L 3-absorption edge has been designed and built to remediate these difficulties. Due to the confocal nature of the analyzer system, the majority of extrinsic scattering is rejected, yielding a clean low-energy excitation spectrum of an iridate Sr2IrO4 sample in a DAC cell. Furthermore, the energy resolution of different configurations of the collimating and analyzing optics are discussed.

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High-pressure developments for resonant X-ray scattering experiments at I16

Journal of Synchrotron Radiation ◽

10.1107/s1600577519016308 ◽

2020 ◽

Vol 27 (2) ◽

pp. 351-359

Author(s):

I. Povedano ◽

A. Bombardi ◽

D. G. Porter ◽

M. Burt ◽

S. Green ◽

...

Keyword(s):

High Pressure ◽

Low Temperature ◽

The Body ◽

X Ray ◽

X Ray Scattering ◽

Scattering Geometry ◽

Diamond Anvil ◽

Membrane Cell ◽

Ray Scattering

An experimental setup to perform high-pressure resonant X-ray scattering (RXS) experiments at low temperature on I16 at Diamond Light Source is presented. The setup consists of a membrane-driven diamond anvil cell, a panoramic dome and an optical system that allows pressure to be measured in situ using the ruby fluorescence method. The membrane cell, inspired by the Merrill–Bassett design, presents an asymmetric layout in order to operate in a back-scattering geometry, with a panoramic aperture of 100° in the top and a bottom half dedicated to the regulation and measurement of pressure. It is specially designed to be mounted on the cold finger of a 4 K closed-cycle cryostat and actuated at low-temperature by pumping helium into the gas membrane. The main parts of the body are machined from a CuBe alloy (BERYLCO 25) and, when assembled, it presents an approximate height of 20–21 mm and fits into a 57 mm diameter. This system allows different materials to be probed using RXS in a range of temperatures between 30 and 300 K and has been tested up to 20 GPa using anvils with a culet diameter of 500 µm under quasi-cryogenic conditions. Detailed descriptions of different parts of the setup, operation and the developed methodology are provided here, along with some preliminary experimental results.

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High-energy-resolution diced spherical quartz analyzers for resonant inelastic X-ray scattering

Journal of Synchrotron Radiation ◽

10.1107/s1600577517018185 ◽

2018 ◽

Vol 25 (2) ◽

pp. 373-377 ◽

Cited By ~ 7

Author(s):

Ayman H. Said ◽

Thomas Gog ◽

Michael Wieczorek ◽

XianRong Huang ◽

Diego Casa ◽

...

Keyword(s):

Energy Resolution ◽

Absorption Edge ◽

High Energy ◽

Fabrication Process ◽

High Energy Resolution ◽

Magnetic Excitations ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

A novel diced spherical quartz analyzer for use in resonant inelastic X-ray scattering (RIXS) is introduced, achieving an unprecedented energy resolution of 10.53 meV at the IrL3absorption edge (11.215 keV). In this work the fabrication process and the characterization of the analyzer are presented, and an example of a RIXS spectrum of magnetic excitations in a Sr3Ir2O7sample is shown.

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Nuclear resonant inelastic X-ray scattering at high pressure and low temperature

Journal of Synchrotron Radiation ◽

10.1107/s1600577515003586 ◽

2015 ◽

Vol 22 (3) ◽

pp. 760-765 ◽

Cited By ~ 9

Author(s):

Wenli Bi ◽

Jiyong Zhao ◽

Jung-Fu Lin ◽

Quanjie Jia ◽

Michael Y. Hu ◽

...

Keyword(s):

High Pressure ◽

Low Temperature ◽

Density Of States ◽

National Laboratory ◽

Argonne National Laboratory ◽

Phonon Density ◽

Phonon Density Of States ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

A new synchrotron radiation experimental capability of coupling nuclear resonant inelastic X-ray scattering with the cryogenically cooled high-pressure diamond anvil cell technique is presented. The new technique permits measurements of phonon density of states at low temperature and high pressure simultaneously, and can be applied to studies of phonon contribution to pressure- and temperature-induced magnetic, superconducting and metal–insulator transitions in resonant isotope-bearing materials. In this report, a pnictide sample, EuFe2As2, is used as an example to demonstrate this new capability at beamline 3-ID of the Advanced Photon Source, Argonne National Laboratory. A detailed description of the technical development is given. The Fe-specific phonon density of states and magnetism from the Fe sublattice in Eu57Fe2As2at high pressure and low temperature were derived by using this new capability.

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