Dielectric properties of low-temperature sintering Ba₅LaMgNb₉O₃₀ ceramic with Li₃NbO₄ addition under nitrogen atmosphere

Ba₅LaMgNb₉O₃₀ ceramics with the addition of Li₃NbO₄ sintered under nitrogen atmosphere were synthesized and characterized. The phase structure, microstructure, dielectric properties and impedance spectroscopy of the prepared ceramics were investigated. All samples showed a diffuse phase transition and the diffuse exponent γ was calculated. With the addition of Li₃NbO₄, Li⁺ could enter the C-sites of BLMN ceramics, which modified the composition of the tungsten bronze structure and improved the performance. Results show that addition of Li₃NbO₄ decreased the sintering temperature of BLMN ceramics to 1050 °C and improved dielectric properties of nitrogen-sintered BLMN ceramics. Impedance spectroscopy analysis indicated that the performance for nitrogen-sintered ceramics was comparable to air-sintered samples at the temperature below 400 °C. The dielectric properties of BLMN ceramics were influenced by the amount of Li₃NbO₄, and the 15 wt% Li₃NbO₄-added BLMN ceramic sintered at 1050 °C in nitrogen for 3 h showed good dielectric properties at 1 MHz of ε_r = 122.19, tanδ = 0.00686 and τ_ε = −631 ppm/°C. The Li₃NbO₄-added BLMN ceramics have application potential for the multilayer ceramic capacitors co-fired with base metal electrode.