Microwave dielectric properties of NiO-V2O5 ceramic system for LTCC applications

Abstract

Novel NiO-V₂O₅ ceramics were synthesized using a solid-state reaction route, and the microwave dielectric properties of NiV₂O₆ and Ni₂V₂O₇ compounds within this system were systematically investigated for the first time. NiV₂O₆ was identified as having a triclinic structure with the P1(2) space group, while Ni₂V₂O₇ exhibited a monoclinic structure belonging P2₁/c(14) space group. The influence of intrinsic and extrinsic factors on the microwave dielectric properties was thoroughly examined. Moreover, the FWHM (Full Width at Half Maximum) of the Raman analysis peak was found to strongly correlate with the dielectric loss. An optimal combination of microwave dielectric properties, with ε_r = 10.6, Q×f = 55,000 GHz, τ_f = –28.8 ppm/°C, and ε_r = 6.8, Q×f = 60,000 GHz, τ_f = –8.9 ppm/°C, can be obtained for NiV₂O₆ and Ni₂V₂O₇ when sintered at 710 °C and 730 °C, respectively. In particular, the Ni₂V₂O₇ ceramic, with its low ε_r, high Q×f, and small τ_f, shows great promise for today’s 5G/6G high-frequency applications. Furthermore, both ceramics demonstrated excellent chemical compatibility with silver, establishing them as promising materials for low-temperature co-fired ceramic (LTCC) applications operating in the microwave frequency range or higher.