This title appears in the Scientific Report :
2020
The design of the new clamp cells for High Pressure neutron scattering and magnetization measurements
The design of the new clamp cells for High Pressure neutron scattering and magnetization measurements
The fundamental requirement to study high-pressure effects is the availability of suitable pressure devices. Their design has to be tailored to the experimental demands regarding the intended pressure, the employed instrumentation and the expected scientific results.Our work presents the development...
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Personal Name(s): | Eich, Andreas (Corresponding author) |
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Su, Y. / Hutanu, V. / Georgii, R. / Beddrich, L. / Caron, L. / Friese, K. / Grzechnik, A. | |
Contributing Institute: |
Streumethoden; JCNS-2 JARA-FIT; JARA-FIT Streumethoden; PGI-4 |
Imprint: |
2020
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Conference: | 58th European High Pressure Research Group International Conference, Hotel Smy Puerto de la Cruz,Tenerife (Spain), 2020-09-06 - 2020-09-11 |
Document Type: |
Poster |
Research Program: |
Jülich Centre for Neutron Research (JCNS) Materials and Processes for Energy and Transport Technologies Quantum Condensed Matter: Magnetism, Superconductivity Controlling Collective States Controlling Collective States |
Publikationsportal JuSER |
The fundamental requirement to study high-pressure effects is the availability of suitable pressure devices. Their design has to be tailored to the experimental demands regarding the intended pressure, the employed instrumentation and the expected scientific results.Our work presents the development of high pressure devices for two experimental methods: neutron scattering on polycristalline and single crystalline samples and macroscopic magnetization measurements.For the high-pressure neutron experiments, one of the most common types of devices is the clamp cell [1]. One of the characteristic features of this device is that the pressure is applied and fixed ex-situ, before the cell is transferred into the experimental setup. While the pressure can thus not be changed in-situ, the advantage of this design is the liberty to use the cell independently in various setups.The use of neutron radiation for scattering experiments on the one hand requires comparatively large samples and thus a large sample space within the cell. On the other hand, due to the high penetration depth of neutron radiation a rather massive design of the cells is possible, provided that neutron-transmissive materials are used.Our cell design has been specifically developed for neutron scattering experiments at low temperatures in the closed-cycle cryostats on the instruments DNS (a diffuse scattering neutron time-of-flight spectrometer), MIRA (a cold three axes spectrometer with optional focussing guides and polarization analysis), and POLI (a polarized hot neutron diffractometer) at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching, Germany. The cell (Fig. 1) has been produced in two variants (one made from CuBe and one made from NiCrAl “Russian Alloy”), working up to about 1.1 GPa and 1.5 GPa, respectively. Since both CuBe and NiCrAl have a very low paramagnetic moment, the cells have low magnetic background, allowing also measurements of magnetic properties.First tests of the cell have been performed to calibrate the load/pressure-curve of the CuBe cell (up to 1.1 GPa, slightly exceeding the calculated limit of about 1.0 GPa), to estimate cell attenuation and background, and to measure magnetic reflections.Ultimately, these cells are intended for high pressure measurements at ultra-low temperatures and in combination with an applied magnetic field.Figure 1. Schematic drawing of the neutron clamp cell.A second high-pressure cell (Fig. 2) has been developed for temperature-dependent magnetization measurements in a commercially available MPMS (Magnetic Properties Measurement System) from Quantum Design as well as for neutron scattering experiments at MLZ. The cell is also built from NiCrAl, allowing measurements up to 1.5 GPa, higher than with similar commercial pressure cells.Figure 2. Schematic drawing of the magnetization clamp cell.Further tests under various conditions (temperature, pressure, magnetic field) are planned for both cells. The results will help both to establish the present cells and to optimise the design of subsequent cells.Acknowledgements: This work was supported by the project 05K19PA2 from the Bundesministerium für Bildung und Forschung (BMBF). The instrument POLI at MLZ is operated by RWTH Aachen University in cooperation with FZ Jülich (Jülich-Aachen Research Alliance JARA).[1] S. Klotz, Techniques in High Pressure Neutron Scattering. CRC Press 2013. |