Percolation behavior of Ag in Ge16Sb12Se72 glassy matrix and its impact on corresponding ionic conductivity

0498997 - ÚMCH 2020 RIV NL eng J - Journal Article
Patil, D. S. - Konale, M. - Cozic, S. - Calvez, L. - Zima, Vítězslav - Wágner, T. - McCloy, J. S. - Le Coq, D.
Percolation behavior of Ag in Ge16Sb12Se72 glassy matrix and its impact on corresponding ionic conductivity.
Journal of Alloys and Compounds. Roč. 782, 25 April (2019), s. 375-383. ISSN 0925-8388. E-ISSN 1873-4669
Institutional support: RVO:61389013
Keywords : percolation behavior * diffusion coefficient * ionic conductors
OECD category: Inorganic and nuclear chemistry
Impact factor: 4.650, year: 2019
Method of publishing: Open access
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01990469/file/Patil%20et%20al_2018_Percolation%20behavior%20of%20Ag%20in%20Ge16Sb12Se72%20glassy%20matrix%20and%20its%20impact%20on.pdf

In the present article, the silver diffusion behavior and its influence on ionic conduction have been studied from a series of glass samples Agx(Ge16Sb12Se72)100-x with 0 ≤ x ≤ 25. A non-linear evolution of the ionic conduction as a function of Ag concentration was found and attributed to a variation in the diffusion mechanism following the Ag rate. The glasses with Ag concentration lower than 5 at. % i.e. for Ag0.2 to Ag1, the Ag+ diffusion mainly occurs via a percolation mechanism, whereas for the Ag concentration from Ag5 up to Ag15, a hopping mechanism is prevailing. However, for Ag5 the diffusion occurs with mixed mechanism i.e. percolation + hopping way. For the Ag content higher than 15 at. % the diffusion occurs via a correlated walk and it was found that the repulsive nature between the Ag+ ions in the high concentrated sample due to much shorter distance does not show self-blocking nature. Additionally, the samples show a transition from electronic to ionic conductivity. From Raman analysis a correlation between the content of Ag and the type of GeSe4/2 tetrahedron, corner or edge-shared, which takes place in the structure, was evidenced. Finally, the results allow a better understanding of the mechanism of the Ag conduction in the glasses of the Ge-Sb-Se system using the random-walk (RW) model.
Permanent Link: http://hdl.handle.net/11104/0291297