Microwave Dielectric Properties of ATe₃O₈ (A = Sn, Zr) Ceramics

ATe₃O₈ (A = Sn, Zr) ceramics were investigated as a promising dielectric materials for low temperature cofired ceramics (LTCC) applications. The ATe₃O₈ ceramics were synthesized using solid state reaction method by sintering in the temperature range 600 to 800 °C. The structure and microstructure of the ceramics were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. The dielectric properties of the ceramics were studied in the frequency range 4–6 GHz. The SnTe₃O₈ ceramic has a dielectric constant (ε_r) of 37.3, quality factor (Q_u×f) of 9600 GHz, and temperature coefficient of resonant frequency (τ_f) of 223 ppm/°C, respectively. Ceramics with the composition 0.9TeO₂–0.1SnTe₃O₈ has ε_r of 26.7, Q_u×f of 10000 GHz, and a τ_f of 32 ppm/°C when sintered at 650 °C/2 h. ZrTe₃O₈ has relatively high ε_r of 67.5, Q_u×f of 1800 GHz, and high positive τ_f of 362 ppm/°C.