Magnetism of the spin-chain compound Ca(3)Co(1.9)Fe(0.1)O(6): magnetization and neutron diffraction study.

We report the results of the dc magnetization and neutron diffraction studies of the quasi-one-dimensional spin-chain compound Ca(3)Co(1.9)Fe(0.1)O(6). Rietveld refinement of neutron powder diffraction pattern at 100 K confirmed that Fe ion was located at trigonal prism site 6a (0, 0, 1/4). The dc susceptibility obeys the Curie-Weiss law. The appearance of additional magnetic Bragg peaks in the low temperature neutron powder diffraction patterns mainly indicates an antiferromagnetic ordering. The magnetic reflections can be indexed with a propagation vector K = (0, 0, 1), referred to the space group R (3) over barc (hexagonal setting), and indicate that the centering translations have been lost in the magnetic structure.