%0 Journal Article
%A Tegel, M.
%A Hummel, F.
%A Su, Y.
%A Chatterji, T.
%A Brunelli, M.
%A Johrendt, D.
%T Non-stoichometry and the magnetic structure of Sr2CrO3FeAs
%J epl
%V 89
%@ 0302-072X
%C Les Ulis
%I EDP Sciences
%M PreJuSER-8899
%P 37006
%D 2010
%Z This work was financially supported by the German Research Foundation (DFG). MT would like to thank Dr K. ROMER for financial support.
%X 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.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000274848600020
%R 10.1209/0295-5075/89/37006
%U https://juser.fz-juelich.de/record/8899