Time-of-flight neutron powder diffraction studies on a chiral two-dimensional molecule-based magnet

The magnetic structure of a chiral molecule-based magnet, [Cr(CN)(6)][Mn(S)-pnH(H2O)](H2O), has been studied using neutron powder diffraction as a function of temperature in the range from 4 K to 300 K. The 020 and 022 magnetic reflections were clearly observed below T-c = 38 K. On the basis of the intensity analysis of magnetic reflections, it was concluded that the magnetic structure is noncollinear ferrimagnetic with the magnetic (Shubnikov) space group P2(1)2'(1)2'(1) and magnetic moments of Cr and Mn atoms are mutually antiparallel along a direction near the a-axis. Our findings imply that the long-period magnetic structure, if exists, is not a helical structure but a conical one.