Time-of-Flight Neutron Powder Diffraction Studies on a Chiral Two-dimensional Molecule-based Magnet

Abstract

The magnetic structure of a chiral molecule-based magnet, [Cr(CN) 6 ][Mn( S )-pnH(H 2 O)](H 2 O), 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 P 2 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.