Antiferromagnetic ordering of the layered cerium carbide halide Ce2C2X2 (X = Br, I)

Complete text of publication follows. The compound Ce2C2X2 crystallizes with a layered structure which has close-packed arrangement of X-Ce-Ce-X slabs. C2 units are located within the Ce6 octahedral interstices. Depending on the stacking sequence there exist two phases (1s- and 3s-stacking variants). Powder magnetic susceptibility measurements suggested an antiferromagnetic ordering transition below 13 K for Ce2C2Br2 and 15 K for Ce2C2I2. Neutron powder diffraction experiments have been performed on two samples, Ce2C2X2 (X = Br, I). The magnetic properties of the Ce2C2X2 phases are discussed as well as their magnetic structures as obtained from refinement using the Rietveld method. (author)