Abstract
Using X-ray diffraction and SEM methods, as well as measurements of the microwave dielectric properties, a section of the ternary Bi2O3–TiO2–WO3 system has been investigated at 1100°C. Within this system the formation of pyrochlore has been detected, and it was revealed that WO3 incorporates into the B sites of the pyrochlore crystal lattice. Charge compensation due to W6+ incorporation occurs primarily via the formation of A site vacancies. With this addition the pyrochlore's unit cell decreases, and reaches its lowest value for ∼13 mol.-% of added WO3. The permittivity of the pyrochlore phase is relatively high and decreases with increasing W content, whereas Q × f increases with increasing W content.