Journal Article

PreJuSER-8899

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Non-stoichometry and the magnetic structure of Sr2CrO3FeAs

Tegel, M. ; Hummel, F. ; Su, Y.FZJ* ; Chatterji, T.FZJ* ; Brunelli, M. ; Johrendt, D.FZJ*

2010
EDP Sciences Les Ulis

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Please use a persistent id in citations: doi:10.1209/0295-5075/89/37006

Abstract: The iron arsenide Sr2CrO3FeAs with the tetragonal Sr2GaO3CuS-type structure was synthesized and its crystal structure re-determined by neutron powder diffraction. In contrast to previous X-ray crystallographic studies, a mixed occupancy of chromium and iron was found within the FeAs4/4 layer (93 +/- 1%Fe : 7 +/- 1%Cr). We suggest that the partial Cr-doping at the Fe site is the reason for the absence of a spin-density-wave anomaly and superconductivity in this compound. Additional experiments via neutron polarization analysis revealed short-range spin correlations below similar to 100 K and long-range antiferromagnetic ordering below T-N = 36 K with a magnetic propagation vector of q = (1/2, 1/2, 0). The Cr3+ -ions form a collinear magnetic structure of the C-type in the magnetic space group C(P)mma' (a' = a-b, b' = a+b, c' = c), where Cr3+-ions occupy the 4g (0, 1/4, z) Wyckoff position. The magnetic moments are aligned along the orthorhombic a'-axis. At 3.5 K, an ordered magnetic moment of 2.75 +/- 0.05 mu B for the Cr3+ -sublattice was refined.

Keyword(s): J

Note: This work was financially supported by the German Research Foundation (DFG). MT would like to thank Dr K. ROMER for financial support.

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Contributing Institute(s):

1. Streumethoden (IFF-4)
2. Neutronenstreuung (IFF-5)
3. JCNS (Jülich Centre for Neutron Science JCNS (JCNS) ; JCNS)

Research Program(s):

1. BioSoft: Makromolekulare Systeme und biologische Informationsverarbeitung (P45)
2. Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) (P55)

Experiment(s):

1. DNS: Diffuse scattering neutron time of flight spectrometer (NL6S)

Appears in the scientific report 2010

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Database coverage:
JCR ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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