Nanocomposites and nanomaterials

The comparative study of 8YSZ zirconia powders and their ceramics
Ihor Polishko1, Yehor Brodnikovskyi1, Ruslana Horda2, Dmytro Brodnikovskyi1, Iryna Brodnikovska1, Leonid Kovalenko3, Natalia Lysunenko1, Mykola Brychevskyi1, Oleksandr Vasylyev1, Anatoliy Belous3
1 Institute for Problems of Materials Science, Krzhizhanovsky Str., 3, Kyiv, 03680, Ukraine
E-mail: polishko.ihor@gmail.com 
2 Institute for Biocolloidal Chemistry, Academician Vernadskyi Blv., 42, Kyiv, 03142, Ukraine
3 Institute of General and Inorganic Chemistry, 32/34 Academician Palladin Ave., Kyiv, 03142, Ukraine

Zirconia ceramics made of different nano-sized powders were compared. The different structure of the zirconia was achieved by sintering at different temperatures in the 1100-1500 °C interval.
Zirconia stabilized with 8-mol. % Y2O3 (8YSZ) powder manufactured mainly by Tosoh, DKKK (Japan) companies is considered as the state-of-the-art material for SOFC electrolyte and electrodes owing to its high ionic conductivity, mechanical and chemical stability in both oxidation and reduction environments. 
Ukraine has own zirconia-sand deposit that is the third in the World and practically the only in the Northern hemisphere [1]. Ukrainian companies, Science & Technology Centre Novitech and Zirconia Ukraine Ltd., have developed zirconia powders with different stabilization, currently 8YSZ and 1Ce10ScSZ optimized for electrolyte and electrode applications.
The mechanical behavior and electrical properties of 8YSZ ceramics were studied. It was found that Novitech 8YSZ powder is ensuring higher mechanical strength and electrical conductivity than the Tosoh one. Namely, at the same level of porosity (~4 %) samples made of Novitech and Tosoh powders at the same technological route demonstrated mechanical strength of 181 and 114 MPa and electrical conductivity of 2.34∙10-3 and 1.2∙10-3 S/cm, respectively.

1.	O. Vasylyev, Y. Brodnikovskyi, M. Brychevskyi I. Polishko, S Ivanchenko, V. Vereshchak. From Powder to Power: Ukrainian Way // SF Journal of Material and Chemical Engineering. - 2018.- 1(1). -P. 1-12.