The exploration of high-performance dielectric ceramics with dielectric constants lower than 10 is of great significance for the next generation of wireless communication. In this study, we reported the Yb₂Si₂O₇ (YSO) dielectric ceramics synthesized using a facile solid-state reaction technique. X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterization confirmed that YSO ceramics had a monoclinic structure. At a sintering temperature of 1500 °C, the sintered sample reached a maximum relative density of 96% and demonstrated the best dielectric properties: dielectric constant (ε_r) = 7.57, Q×f = 78,645 GHz (Q is quality factor, and f is the resonant frequency of 13.5 GHz), andtemperature coefficient of the resonant frequency (τ_f) = −13.5 ppm/°C. Moreover, Raman analysis revealed that the Si–O bond dominated the lattice vibration, and the full width at half maximum (FWHM) of the strong peak at 922 cm⁻¹ was inversely proportional to the Q×f value. According to the Phillips–van Vechten–Levine (P–V–L) theory, the values of Q×f and τ_f are affected primarily by the Si–O bond, while ε_r is influenced mainly by the Yb–O bond. YSO ceramics demonstrated excellent dielectric properties in the terahertz band (ε_r = 8.13, Q×f = 112,758 GHz), making them promising candidates for future applications in the terahertz band.

Sr_0.7Bi_0.2TiO₃ (SBT) by increasing the proportion and size of polar nano-region. Meanwhile, the BDS remains a high level with x ≤ 0.38 attributed to the addition of KBT with a large band gap. As a result, the 0.62SBT-0.38KBT exhibits a high energy storage density of 2.21 J/cm³ with high η of 91.4% at 220 kV/cm and superior temperature stability (−55 ~ 150 °C), frequency stability (10 ~ 500 Hz) and fatigue resistance (10⁵ cycles). Moreover, high pulsed discharge energy density (1.81 J/cm³), high power density (49.5 MW/cm³) and great thermal stability (20 ~ 160 °C) are achieved in 0.62SBT-0.38KBT. Based on these excellent properties, the 0.62SBT-0.38KBT are suitable for pulsed power systems. This work provides a novel strategy and systematic study for improving energy storage properties of SBT.