Piskin, CeremKaracasulu, LeventBortolotti, MauroVakifahmetoglu, Cekdar2021-11-062021-11-0620212666-5395https://doi.org/10.1016/j.oceram.2021.100159https://hdl.handle.net/11147/11208Bortolotti, Mauro/0000-0002-7213-6316; Karacasulu, Levent/0000-0003-4710-2816KxNa1-xNbO3 (0 < x < 1) were synthesized via hydrothermal method using niobium dioxide (NbO2) as the niobium source instead of the most common one, Nb2O5. Potassium-rich KxNa1-xNbO3 (x > 0.5) was obtained from 8 M total hydroxide concentration after 6 h of reaction at 200 degrees C. Rietveld refinement of the XRD data revealed that all samples exhibited the secondary NaNbO3 phase. However, the lowest amount (3.74 vol%) was obtained for 24 h of reaction under 10 M alkaline solution. After 3 h of reaction, dodecahedra shaped hexaniobate phase (KxNa8-xNb6O19.nH(2)O) was observed. Those structures were, subsequently, replaced by similar to 3 mu m cube shaped KNN crystals, obtained under 10 M reaction in 24 h time period.eninfo:eu-repo/semantics/openAccessPotassium Sodium NiobateHydrothermal SynthesisNiobium DioxideArticle2-s2.0-8510945128710.1016/j.oceram.2021.100159