Properties of the organic conductors (TMTSF)/sub 2/M(tht)/sub 2/, M=Cu and Ni; relation to the selenium analogues.

Summary form only given. Previous studies on (TMTSF)/sub 2/M(tds)/sub 2/, (tds=[bis(trifluoromethyl)ethylene]diselenolato), M=Ni, Cu and Pt, revealed the appearance of two different phases (/spl alpha/ and /spl beta/) for the M=Ni and Pt based compounds. While the crystals of the (/spl alpha/-phase showed an unusual first order phase transition, as reported previously, the /spl beta/-phase crystals showed no such transition and present a well defined metallic behaviour down to /spl sp/160K. In order to get a better understanding of the different phases, the analogues of Cu and Ni, containing the sulfur ligands (tht=thiete or [bis(trifluoromethyl)ethylene]dithiolato) were prepared and their physical properties studied. In (TMTSF)/sub 2/M(tht)/sub 2/ compounds, with M=Cu and Ni, only one type of crystals, appearing as thin needles and corresponding to the /spl beta/-phase of (TMTSF)/sub 2/M(tds)/sub 2/, were obtained by electrocristalisation. Single crystal thermopower, S, and electrical resistivity, p, measurements along the needle axis give S/sub RT//spl ap/1-2 /spl mu/V/K and prt/spl ap/40-12OS/cm, both denoting a clear metallic regime down to ca. 70K, where a M-I transition takes place. These transport properties, as well as magnetic measurements, both by static magnetic susceptibility and EPR, will be compared to those of the tds analogues.