Sintering behavior, crystal structure, and microwave dielectric properties of a novel NaY9Si6O26 ceramic

Abstract This study investigates NaY 9 Si 6 O 26 ceramics prepared through the solid‐phase method, focusing on their microwave dielectric properties and crystallographic characteristics. X‐ray diffraction analysis reveals a hexagonal crystal structure for NaY 9 Si 6 O 26 ceramics within the P 63/ m (176) space group. Rietveld refinement analysis precisely determines the lattice constants as a = b = 9.3423 Å, c = 6.7524 Å, and a unit cell volume of V = 510.3877 Å 3 . Additionally, Raman spectroscopy unveils a noteworthy correlation between the quality factor and the full width at half maximum of the A 1g (O) mode at 878 cm −1 . The structural attributes, including lattice fringes and diffraction patterns of hexagonal NaY 9 Si 6 O 26 ceramics, are elucidated through transmission electron microscopy. Of significance are the microwave dielectric properties of NaY 9 Si 6 O 26 ceramics sintered at 1465°C, revealing a relative permittivity ( ε r ) of 10.42, an impressive Q × f product of 33 766 GHz (at f = 11.14 GHz), and a temperature coefficient of resonant frequency ( τ f ) of −28.7 ppm/°C. This comprehensive investigation contributes to the understanding of both the structural and microwave dielectric characteristics of NaY 9 Si 6 O 26 ceramics, with potential applications in advanced electronic devices.