Nanocomposites and nanomaterials

Electrical conductivity of Ag6PS5I-based superionic ceramic prepared from nanopowder
Shender I.A.1, Pogodin A.I.1, Filep M.J.1, Kokhan O.P.1,            Studenyak I.P.1, Kopčanský P.2
1 Uzhhorod National University. 
Pidgirna Str. 46, Uzhhorod - 88000, Ukraine.
E-mail: iryna.shender@uzhnu.edu.ua
2 Institute of Experimental Physics, Slovak Academy of Sciences. 
47, Watsonova Str., 04001 Košice, Slovakia.

Recently, an active search for new materials is underway and ways to create on the basis of already known materials effective materials for solid-state batteries are being developed. Superionic ceramic materials are those materials that can replace single crystals due to their efficiency, manufacturability and economy
Synthesis of Ag6PS5I was carried out in vacuumed to 0.13 Pa quartz ampoules using simple substances: silver (99.995%), phosphorus (99.999%), sulfur (99.999%), and pre-synthesized binary argentum (I) iodide, additionally purified by directional crystallization method, taken in stoichiometric ratios.
Nanocrystalline powder for preparing ceramic sample obtained by grinding in a planetary ball mill PQ-N04 for 60 min with a speed of 200 rpm. The powder obtained as a result of grinding were investigated using XRD and SEM techniques. Pressing of sample was carried out at a pressure of ~ 400 MPa, annealing - at 973 K during 36 hours. As a result of recrystallization, the average size of crystallites for ceramic is ~ 3.3 µm.
Investigation of the electrical conductivity of ceramic sample based on Ag6PS5I superionic conductor was carried out by impedance spectroscopy method. It should be noted that for ceramic sample the obtained dependence of the total electrical conductivity on the frequency are of a typical behavior; an increase in conductivity with a frequency is observed, being characteristic of materials with ionic conductivity in solids. For the detailed studies of frequency behavior of electrical conductivity and its separation into ion and electron components, a standard approach using electrode equivalent circuits and their analysis on Nyquist plots was used. It should be noted that ceramic prepared on the basis of Ag6PS5I nanopowder characterized by a low value of electronic conductivity (σion>σel). It is established that the value of ionic and electronic components of electrical conductivity is 4.80×10-4 S/cm and 5.22×10-5 S/cm, respectively.