ORDER-DISORDER TRANSITION IN SILVER-INTERCALATED NIOBIUM DISULFIDE COMPOUNDS .2. MAGNETIC AND ELECTRICAL-PROPERTIES

The dc electrical conductivity, the Hall effect, the thermoelectric power, and the magnetic susceptibility of Ag-intercalated 2H-NbS2 have been measured as a function of temperature for various Ag contents in Ag(x)NbS2. The electrical resistivity exhibits a strong anomaly near T = 124 K. The Hall and Seebeck coefficients only show weak anomalies at this temperature. These results are related to the structural changes occurring at the phase transition near T = 124 K. The Hall and Seebeck coefficients have opposite signs for all compositions considered and point to a two-carrier-type conduction. The magnetic measurements show an increased filling of the Nb d(z)2 band with higher Ag content and are in qualitative agreement with a rigid-band model for intercalation.