抄録
The conductivities of synthetic Ag3AsS3 and Ag3AsSe3 have been measured as a function of temperature and frequency by the complex impedance method. Their impedance plots exhibited the characteristic semicircles which were attributed to ionic conduction behaviors in the bulk and the grain boundary. The transport number of charge carrying species in Ag3AsS3 was determined by the Tubandt method. The electronic contribution to the total conductivity of Ag3AsS3 was negligible small at room temperature; less than 1%. The logσT versus 1/T plot of Ag3AsS3 had a kink of the slope near about 375 K. The activation energies below and above 375 K are evaluated as 0.23 and 0.35 eV, respectively. Ag3AsSe3, measured only below about 330 K, gave an activation energy of 0.24 eV. The magnitude of the conductivity of Ag3AsSe3 is almost ten times larger than that of Ag3AsS3 below 375 K. The conductivities of Ag3AsS3, 1.5×10−3 S/cm at 427 K, and of Ag3AsSe3, 1.6×10−3 S/cm at 331 K, are sufficient magnitudes as superionic conductors.
