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

This study investigates NaY9Si6O26 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 NaY9Si6O26 ceramics within the P63/m (176) space group. Rietveld refinement analysis precisely determines the lattice constants as a = b = 9.3423 & Aring;, c = 6.7524 & Aring;, and a unit cell volume of V = 510.3877 & Aring;(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 NaY9Si6O26 ceramics, are elucidated through transmission electron microscopy. Of significance are the microwave dielectric properties of NaY9Si6O26 ceramics sintered at 1465 degrees C, revealing a relative permittivity (epsilon(r)) of 10.42, an impressive Q x f product of 33 766 GHz (at f = 11.14 GHz), and a temperature coefficient of resonant frequency (tau(f)) of -28.7 ppm/degrees C. This comprehensive investigation contributes to the understanding of both the structural and microwave dielectric characteristics of NaY9Si6O26 ceramics, with potential applications in advanced electronic devices.