Conference Presentation (After Call)

FZJ-2019-00378

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Structure analysis with hot neutrons and under extreme conditions on HEIDI

Meven, M. (Corresponding author)MLZ*FZJ*RWTH* ; Sazonov, A.FZJ* ; Grzechnik, A.RWTH* ; Roth, G.RWTH*

2018

Abstract: The single crystal diffractometer HEiDi at the 20 MW neutron source Heinz Maier-Leibnitz Zentrum (MLZ) uses hot neutrons for structural studies on various hot topics related to physics, chemistry and mineralogy by offering high flux, high resolution and large q range, low absorption and high sensitivity for light elements.High temperature studies on Nd2NiO4+δand Pr2NiO4+δ brownmillerites concerning their oxygen diffusion pathways reveal a double well potential pointing towards the interstitial vacancy sites, creating a quasicontinuous shallow energy diffusion pathway between apical and interstitial oxygen sites (Ceretti et al.). Future studies will use a special mirror furnace which allows temperatures > 1000°C and atmospheres with various oxygen content. Various multiferroic compounds from the melilite family, e.g. Ba2CoGe2O7 andCa2CoSi2O7 were studied in order not only to reveal their orthorhombic antiferromagnetic magnetic order structures at low temperature but also the risks of misinterpretation of structural data due to multiple scattering (Sazonov et al.). Different studies on silicateand phosphate-based gems like brazilianite, hureaulite and axinite (G.D. Gatta et al.) show the broad variety of hydrogen bonds with different degrees of disorder. Aside from scientific examples this contribution will give an overview of the most recent instrumental features (esp. pressure cell development (BMBF funding 05K16PA3) and the new mirror furnace).

Keyword(s): Instrument and Method Development (1st) ; Energy (1st) ; Chemical Reactions and Advanced Materials (1st) ; Crystallography (2nd) ; Instrument and Method Development (2nd)

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. Streumethoden (JCNS-2)
3. Heinz Maier-Leibnitz Zentrum (MLZ)

Research Program(s):

1. 6G4 - Jülich Centre for Neutron Research (JCNS) (POF3-623) (POF3-623)
2. 6G15 - FRM II / MLZ (POF3-6G15) (POF3-6G15)
3. 6213 - Materials and Processes for Energy and Transport Technologies (POF3-621) (POF3-621)
4. 144 - Controlling Collective States (POF3-144) (POF3-144)

Experiment(s):

1. HEiDi: Single crystal diffractometer on hot source (SR9b)

Appears in the scientific report 2018

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