Abstract

FZJ-2022-01717

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Developments in High Pressure Clamp Cells for Neutron Scattering at the MLZ

Eich, A.FZJ* ; Friese, K.FZJ* ; Meven, M.FZJ* ; Hölzle, M.FZJ* ; Su, Y.FZJ* ; Müller, T.FZJ* ; Hutanu, V. ; Poli, M. K. B. ; Georgii, R. ; Beddrich, L. ; Grzechnik, A.

2022

Please use a persistent id in citations: http://hdl.handle.net/2128/30844

Abstract: The availability of pressure devices adapted tothe experimental demands (intended pressure,probing method, instrumental environment, etc.)is the fundamental requirement for the study ofhigh-pressure effects on any material property.Our work presents the development of highpressure cells for neutron scattering onpolycrystalline and single-crystalline samples atlow temperatures and with applied magneticfields.In the most common type of device used for high-pressure neutron experiments, the clamp cell[1], the pressure is applied ex situ, allowing its independent and versatile use in various setups.Our clamp cell design has been specifically developed for neutron scattering experiments at lowtemperatures in the closed-cycle cryostats on the instruments DNS (diffuse scattering neutronspectrometer), MIRA (cold three axes spectrometer), and POLI (polarized hot neutrondiffractometer) at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching, Germany [2]. Thecompact monobloc cell is available in two variants, a CuBe alloy and a NiCrAl “Russian Alloy”one, working up to about 1.1 GPa and 1.5 GPa, respectively. Measurements aimed to elucidatemagnetic properties are possible due to the low paramagnetic moment of both alloys.Tests with neutron radiation were performed to calibrate the load/pressure curve of the CuBecell, to estimate its neutron absorption and background, and to measure magnetic reflections. Inaddition, the thermal response of the cells in the instrument cryostat was measured and theexperimental findings were complemented by simulations.A second, modified version of the cell with the same mechanical properties (Fig. 1) wasdeveloped with an optical access path to the inner part of the cell, which additionally enables theuse of ruby luminescence to determine the pressure independent from neutrons. The respectiveload/pressure calibration curves were measured for both cell variants.Ultimately, these cells are intended as standard cells for high pressure measurements ondifferent instruments at MLZ suitable for all available magnets and cryostats down to 1.5 K.

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Contributing Institute(s):

1. Streumethoden (JCNS-2)
2. Streumethoden (PGI-4)
3. JARA-FIT (JARA-FIT)
4. JCNS-FRM-II (JCNS-FRM-II)

Research Program(s):

1. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)
2. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)

Experiment(s):

1. DNS: Diffuse scattering neutron time of flight spectrometer (NL6S)
2. POLI: Polarized hot neutron diffractometer (SR9a)
3. MIRA: Multipurpose instrument (NL6N)

Appears in the scientific report 2022

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Database coverage:

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