The structure of Ag0.167TiS2 has been determined at several temperatures from time-of-flight neutron powder diffraction data. At 305 K, Ag0.167TiS2 is a stage-II complex which belongs to the space groupP3-m1, witha = 3.4161(4)Åandc = 12.100(2)Å. When the temperature is lowered to 13 K, the lattice parameters decrease, but no phase change or superlattice formation is observed. Upon heating to 1123 K, this compound transforms to a stage-I structure belonging to the space groupP3-m1, witha = 3.4676(1)Åandc = 6.2247(4)Å. No further phase changes are observed when the temperature is raised to 1323 K. When this compound is slowly cooled to ambient temperature from 1323 K, it transforms quantitatively to the original stage-II structure. The Rietveld refinements of Ag0.167TiS2 at six temperatures are presented and discussed.
Bibliographical noteFunding Information:
This study has benefited from the use of LANSCE at Los Alamos National Laboratory and IPNS at Argonne National Laboratory. IPNS is funded by the Department of Energy, BES-Materials Science, under Contract W-31-109-Eng-38. We thank R. L. Hitterman at IPNS and A. Williams and A. C. Lawson at LANSCE for assistance in data collection and G. A. Wiegers for helpful conversations. We are grateful to the National Science Foundation for support through Grant DMR-8605937, Arizona State University for the necessary computer time and the use of the X-ray facilities, the Center for Solid State Science at Arizona State University for the use of its Materials Preparation Facility, and M. Wheeler and W. O’Neill for expert assistance in glassblowing.