Novel Series of Low‐Firing Microwave Dielectric Ceramics: (1− x ) Li ₃ Bi ₂ P ₃ O ₁₂ – x TiO ₂

Abstract

A new thermally stable microwave dielectric ceramic with low‐firing temperature in (1− x ) Li 3 Bi 2 P 3 O 12 – x TiO 2 [(1− x ) LBP – x T , 0 ≤ x ≤ 0.6] ceramics system was obtained using conventional solid‐state reaction method. The phase transformation, microstructure, and microwave dielectric properties of materials were investigated using X‐ray powder diffraction ( XRD ), scanning electron microscopy ( SEM ) , and a network analyzer. The LBP ceramic ( x = 0) sintered at 725°C has optimum microwave dielectric properties with relative permittivity (ε r ) of 15.8, Q × f of 26 600 GHz and temperature coefficients of resonant frequency (τ f ) of −130 ppm/°C. The ε r and τ f of (1− x ) LBP – x T ceramics were tailored with increasing x values. At x = 0.55, the ceramic exhibits improved microwave dielectric properties with ε r = 22.1, Q × f = 14 900 GHz and τ f = −2.6 ppm/°C.