Y2GaSbO7: A novel microwave dielectric ceramic with pyrochlore structure.

Ceramics of Y 2 GaSbO 7 (YGSO) were prepared by the solid-state reaction method. The ceramics were confirmed by XRD and TEM to exhibit the Fd-3 m (227) space group and a cubic pyrochlore structure within the temperature range of 1420–1500 °C. XPS verified that the valence states of Y, Ga, and Sb in the ceramics were + 3, + 3, and + 5, respectively. Additionally, the relationship between the FWHM of the notable peak at 775 cm−1 and the Q × f value was elucidated through Raman spectroscopic analysis. The analysis of the P-V-L theory revealed that the Sb-O bond is crucial in determining ε r , while the values of τ f and Q × f are affected by the Y-O bond. At 1460 °C, YGSO ceramics obtained the maximum relative density (97.5%) and the best microwave dielectric properties (ε r = 14.78, Q × f = 50,153 GHz, and τ f = –22.3 ppm/°C). • For the first time, a Y 2 GaSbO 7 microwave dielectric ceramic with a pyrochlore structure was discovered. • The Raman spectra of the ceramics were analyzed, and the valence state was studied using XPS. • TEM analysis confirmed the cubic structure of Y 2 GaSbO 7 ceramics. • SEM images revealed the microstructure of the ceramic grains, with the maximum relative density reaching 97.5%. • The relationship between α , f i , E b , U b , and the dielectric properties of Y 2 GaSbO 7 ceramics was examined using P-V-L theory. [ABSTRACT FROM AUTHOR]