Ultra-low temperature sintering and temperature stable microwave dielectrics of (Mg_1-xZn_x)V₂O₆ (x= 0–0.09) Ceramics

Novel ultra-low firing (Mg_1-xZn_x)V₂O₆(x = 0–0.09) ceramics have been investigated and systematically designed as promising dielectrics for ultra-low temperature co-fired ceramics applications. The X-ray diffraction patterns indicated that all samples crystallized in a monoclinic structure with a space group of C_2/m. Microstructures and lattice parameters are presented and correlated with the microwave dielectric properties of the ceramics. The MgV₂O₆ specimen can be well-sintered at 610°C, the resulting ceramic of which featured an ε_r ~ 8.8, a Q × f ~ 10,300 GHz and a τ_f ~–29.7 ppm/°C. The tunable τ_f value can be adjusted to near zero along with a great promotion in the Q × f of MgV₂O₆ by using a small Zn substitution. In addition, excellent microwave dielectric properties (ε_r ~ 9.3, Q × f ~ 15,300 GHz @15.5 GHz and τ_f ~–3.4 ppm/°C) were obtained for the (Mg_0.93Zn_0.07) V₂O₆specimen sintered at 610°C for 4 h. The specimen is chemically compatible with Al electrodes and could be an ideal ultra-low temperature co-fired ceramics dielectric. Possible applications include the 5 G system, particularly with high frequency regions.