Neutron Diffraction and Magnetic Structure of CsMnCl3

Abstract

The room-temperature (paramagnetic) structure of CsMn${\mathrm{Cl}}_3$ is verified by neutron powder diffraction studies. This compound is found to be a perovskite-related compound (the nine-layer structure) which belongs to the trigonal space group $D_{3d}^5-R\overline{3}m$. The compound is antiferromagnetic below 67 °K; its magnetic structure is deduced from its neutron diffraction pattern at liquid-helium temperature. This structure is of the $G$ type with a $\overrightarrow{\mathrm{k}}$ vector (½, ½, ½) related to the rhombohedral crystallographic lattice. The spin direction is perpendicular to the body diagonal of the rhombohedral unit cell. The magnetic symmetry is monoclinic, belonging to the space group $\frac{C_{2c}2}{m}$. A dipolar energy calculation confirms the spin direction found. A magnetic moment of $(5.5\mathrm{}\pm 0.5){\mu }_B$ is calculated for the ${\mathrm{Mn}}^{+2\mathrm{}}$ ions.