Magnetic Structure of CsCoCl₃ at 4.2 °K

Abstract

Abstract The compound CsCoCl 3 is paramagnetic at room temperature and belongs to the space group D −P6 3 /mmc with two formula units per unit cell (CsNiCl 3 type structure). The neutron diffraction of CsCoCl 3 powder and single crystal samples were studied as a function of sample temperature. A transition to antiferromagnetism was found at T N = 21.5 °K. The magnetic structure determined from the diffraction pattern at 4.2 °K is collinear and consists of ferrimagnetic ab planes stacked antiferromagnetically along the c‐axis with spins parallel to the c‐axis. The magnetic moment consistent with the diffraction at 4.2 °K is (3.0 ± 0.3) and (2.3 ± 0.3) Bohr magnetons per Co 2+ ion according to the powder and single crystal data, respectively. The magnetic unit cell is the hexagonal H‐cell (a = √3a 0 , c = c 0 ) with six formula units per unit cell. This structure belongs to the magnetic space group P6 3 ′/m′cm′ (III ‐ P6 3 ′/m′cm′). The powder and single crystal data show that the magnetic structure near T N is different from the magnetic structure at 4.2 °K.