X-ray diffraction study on spinel compound CuIr2S4 with metal-insulator transition

Crystal structure of the low-temperature phase of the spinel compound CuIr2S4 has been examined by the high-resolution X-ray diffraction. It is found that the low-temperature phase has a triclinic symmetry and eight crystallographically independent Ir sites. These results suggest the possibility of the charge ordering of Ir3+ and Ir4+ ions. (C) 2001 Elsevier Science B.V. All rights reserved.