Preparation and electrical conductivity of (Cu0.5Ag0.5)7SiS5I-based superionic ceramics

Highlights: • The new ceramics were prepared by using of powders with different particles size. • Structural studies were carried out by XRD and microstructural analysis. • Electrical conductivity was measured by means of impedance spectroscopy. -- Abstract: The ceramics based on (Cu_0·5Ag_0.5)₇SiS₅I solid solution of superionic conductor with argyrodite structure were prepared by using the powders with different particles size. The structural studies of powders were performed by XRD technique, while the ceramic samples with different average size of the crystallites were investigated by microstructural analysis. The total electrical conductivity of ceramic samples was measured by impedance spectroscopy in the frequency range from 10 Hz to 2 × 10⁶ Hz and temperature interval from 292 K to 383 K. The contributions of ionic and electronic components into the total electrical conductivity were separated as well as their temperature behavior was studied. The dependences of ionic and electronic conductivity and their activation energies on average size of the crystallites in (Cu_0·5Ag_0.5)₇SiS₅I-based ceramic samples were investigated.