Sintering behaviors and microwave dielectric properties of BaO–MgO–SiO₂ ternary ceramics

In the present work, five compositions in the BaO–MgO–SiO 2 ternary system were chosen, and ceramics were prepared using the solid‐state reaction method. Single phases were formed easily for the first four compositions, and BaMgSi 3 O 8 ceramics were found to be a mixture of both BaSi 2 O 5 and MgSiO 3 , according to X‐ray diffraction results. Among all the compositions, Ba 2 MgSi 2 O 7 ceramic sintered at 1225°C possesses the highest Qf ( Q = 1/dielectric loss = 1/tan δ , f = resonant frequency) value ∼55 010 GHz along with relative permittivity ∼8.0 and temperature coefficient of resonant frequency (TCF) ∼−57.5 ppm/°C. With 3 wt.% BCB (BaO–B 2 O 3 –CuO) additions, Ba 2 MgSi 2 O 7 ceramic was well densified at 950°C with a relative permittivity ∼8.1, Qf value ∼28 920 GHz (at 12.37 GHz) and TCF value ∼‒56.6 ppm/°C. These series ceramics with low relative permittivity values might be good candidates for low‐temperature co‐fire ceramic technology substrate applications.