The crystal structure and electric and microwave dielectric properties of novel scheelite structure NaEr(MoO4)2 ceramics and its application in the S-band

Abstract

In this paper, NaEr(MoO₄)₂ (NEM) ceramics were synthesized via the conventional solid-state reaction method. XRD and TEM analyses revealed that the NEM ceramics exhibited a tetragonal scheelite structure with a space group of I4₁/a (88). Composite impedance spectroscopy was employed to characterize the electrical properties of the NEM ceramics, while Raman spectral analysis provided insights into its lattice vibrations. The microstructures of NEM ceramics were characterized by SEM. The dielectric properties of NEM ceramics, including ε_r and Q × f, exhibited a similar trend to the density. Optimal dielectric properties for NEM ceramics were achieved at 975 °C, with ε_r = 11.08, Q × f = 45 718 GHz, and τ_f = −33.43 ppm °C⁻¹. Furthermore, the relationship between the structure and performance was further investigated utilizing P–V–L theory, far-infrared reflectance spectroscopy, and THz time-domain spectroscopy. Finally, a patch antenna suitable for the S-band was designed and fabricated with NEM ceramics as the substrate material. The research provides valuable insights for both academic investigation and industrial application of tetragonal scheelite structure ceramics.