DC conductivity of GeSeAg glasses at room temperature

Ionic conducting glasses are used as electrolytes in electrochemical applications (microbatteries, sensors, etc.). An interesting superionic amorphous alloy is Ge–Se–Ag where the conducting species is the Ag+ ion. This system is a good glass forming material which does not need high cooling velocities in a wide concentration range in the Se-rich corner. A maximum Ag content of 30 at.% could be introduced into a Se-rich sample with the composition GeSe3 while still retaining the vitreous character. X-ray scattering curves are characterised by a first scattering peak (FSP) located at q≈1 Å−1 which corresponds to an intermediate range order [J. Non-Cryst. Solids 273 (2000) 30]. The fundamental structural unit of the glass is the GeSe4/2 tetrahedra. In this work, we study the electric behaviour of the amorphous GeSeAg system. Glasses of the (GeSe3)100−xAgx system were prepared in the composition range from x=0 to 25 at.%. The electrical characterisation was performed using AC voltages with frequencies ranging from 100 Hz to 100 KHz. The conductivity (σ≈10−4 Ω−1 cm−1 for x=25 at room temperature) shows a monotonous decrease with decreasing Ag concentration. We discuss the relation between the glass structure and their electrical properties.