Ionic and electronic transport in AgI-As2Te3 glasses

108mAg tracer diffusion, ac impedance measurements and Wagner dc polarization experiments show that xAgI⋅(1 − x)As2Te3 glasses (0 ≤ x ≤ 0.8) prepared either by traditional thermal synthesis in vacuum or by mechanical milling exhibit drastic changes in electronic and ionic conductivity as a function of silver iodide content x. The ionic transport increases monotonically by 9 orders of magnitude while the electronic conductivity decreases by a factor of 104 with increasing x. The x < 0.5 glasses are essentially amorphous semiconductors with the silver ion transport number between 10− 8 ≤ tAg+ < 0.5. The AgI-rich compositions, 0.6 ≤ x ≤ 0.8, belong to superionic glasses with the residual electronic conductivity of n-type, 10− 5 ≤ tn ≤ 0.01.