Repozytorium publikacji - Politechnika Gdańska

Ustawienia strony

english
Repozytorium publikacji
Politechniki Gdańskiej

Treść strony

Effect of Bi2O3 Excess on Morphology and Structure of BiNbO4 Ceramics

Goal of the present research was to fabricate BiNbO4 ceramics from the mixture of powders by the solid state reaction route and pressureless sintering at various temperatures (TS =8700C and TS =9100C) and study microstructure, phase composition and crystalline structure of BiNbO4 ceramics. Four batches were fabricated and examined, namely the one fabricated from the stoichiometric mixture of reagent – grade oxide powders, viz. Bi2O3 and Nb2O5 as well as the ones with an excess of 3%, 5% and 10% by mole of Bi2O3. It was found that apart from the main orthorhombic -BiNbO4 phase additional phases, namely tetragonal Bi5Nb3O15, and cubic Bi3NbO7 are possible to form from the mixture of bismuth oxide and niobium oxide. It was found that -BiNbO4 ceramics exhibited the orthorhombic symmetry identified as Pnna (52). However, small differences in elementary cell parameters were found for the samples sintered from stoichiometric and non-stoichiometric mixture of initial powders.

Autorzy