ChemInform Abstract: Magnetic Ordering Within the Layered Terbium Carbide Iodide, Tb2C2I2.

Abstract The compound Tb 2 C 2 I 2 crystallizes with a layered structure (space group= C2/m ), which has a close-packed arrangement of I–Tb–Tb–I slabs. C 2 units are located within the Tb octahedral voids. Powder magnetic susceptibility measurements suggest two antiferromagnetic ordering transitions below 90 K. From the refinement of neutron powder diffraction patterns, the Tb moments order with a propagation vector k =(0,0,0). The refined Tb moments are 8.0(1) μ B at 10 K, and they are aligned antiferromagnetically in the ac plane.