Y2GaSbO7: A novel microwave dielectric ceramic with pyrochlore structure

Ceramics of Y2GaSbO7 (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 εr, while the values of τf 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 (εr = 14.78, Q × f = 50,153 GHz, and τf = –22.3 ppm/°C).