Optimizing microwave dielectric properties of low-temperature sintered Sr/Zn-substituted BaMg2V2O8 by mixing with TiO2

Abstract

Ba_1 − xSr_xMg_2 − yZn_yV₂O₈ compounds, abbreviated as BSMZVO@_xy (x = 0.0–0.2 and y = 0.02), were synthesized with tetragonal structures. The microstructure, molecular structure, and polarization mechanism were investigated using X-ray diffraction, electronic microscopy, Raman spectroscopy, and vector network analyzer. The sintering temperatures (<900°C) and microwave dielectric properties of BSMZVO are significantly impacted by (Sr/Zn)²⁺ substitution and TiO₂ mixing. The BSMZVO@_xy (x = 0.15 and y = 0.02) exhibited encouraging ε_r (12.4–12.7), Q × f (40 054–40 973 GHz), and temperature coefficient of resonance frequency (τ_f ∼ −5.2 to 0.0 ppm/°C) after sintering at 860°C/4 h and 800°C/4 h. For the first time, TiO₂ was added to enhance the density and Q × f value without degrading τ_f. The 0.25 wt.% TiO₂ resulted in optimum ε_r of 13.4, Q × f of 43 636 GHz, and τ_f of +1.8 ppm/°C after sintering at 760°C/4 h. The improved quality factor (Q × f) is linked to the Raman A_1g mode and relative density.