| 초록 |
Dielectric properties of (Mg0.95A0.05)(Ti0.95B0.05)O3 (A=Mg, Zn, B=Ti, Sn) / Polystyrene (PS) composites with various ceramic volume fraction (0.1≤ Vf ≤0.5) were investigated at microwave frequencies. (Mg0.95A0.05)(Ti0.95B0.05)O3 (A=Mg, Zn, B=Ti, Sn) powders were heat-treated at 1400℃ for 4h and then milled for 24h. Composites of (Mg0.95A0.05)(Ti0.95B0.05)O3 (A=Mg, Zn, B=Ti, Sn) / Polystyrene (PS) were prepared by hot-molding technique. For all of the composites, the dielectric constant (K) of the composites showed good frequency stability in the frequency range from 1 to 8GHz. Due to the difference of the dielectric polarizabilities of A-, and B-site ions of (Mg0.95A0.05)(Ti0.95B0.05)O3 (A=Mg, Zn, B=Ti, Sn), the dielectric constants (K) of the composite were changed. With the increasing of ceramic volume fraction (Vf) up to 0.3 Vf, the quality factors (Qf) of the composite were increased and those of the composite with higher Vf of ceramics than 0.3 Vf were decreased. The composite with 0.3 Vf MgTiO3 / 0.7 Vf PS showed the highest quality factor (Qf = 33,000GHz) through the entire range of compositions. Thermal stability of the composite was also discussed by the temperature coefficient of resonant frequency (TCF). |
