A Low-Temperature Firing and Low-Loss SrBi2TeO7 Microwave Dielectric Ceramic for LTCC Applications

The structural characteristics and microwave dielectric properties of SrBi 2 TeO 7 ceramics intended for low-temperature co-fired ceramic (LTCC) applications were investigated. Comprehensive analyses were conducted using x-ray diffraction, structural refinement, transmission electron microscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy. The findings demonstrated that SrBi 2 TeO 7 ceramics possess a pure cubic structure. Scanning electron microscopy characterizes the grain microstructure, revealing a relative density of 95.5% for SrBi 2 TeO 7 ceramic. Optimal microwave dielectric properties were achieved for SrBi 2 TeO 7 ceramics calcined at 765°C, displaying a relative permittivity ( ε r ) of 24.96, a Q  ×  f value of 25,898 GHz ( f  = 6.6 GHz), and a temperature coefficient of resonant frequency ( τ f ) of –80.7 ppm/°C. The combination of low sintering temperature and minimal dielectric loss renders these ceramics advantageous for utilization in LTCC materials.