PHYSICAL-PROPERTIES OF 6R-TAS2

We have characterized powders of 6R-TaS2 by means of (ac and dc) susce ptibility, resistivity, and differential scanning calorimetry. Three p hase transitions are observed below 350 K: a superconducting transitio n with its onset at 2.3 K and transitions (at 80 and 325 K) which invo lve increases in resistivity and decreases in susceptibility upon cool ing. We suggest that the upper two transitions are charge-density-wave transitions; this identification is supported by the strong pressure dependence of the superconducting transition, dT(c)/dP = 0.18 K/kbar. (C) 1995 Academic Press, Inc.