Microwave Dielectric Properties of V₂O₅–Doped (1-x)La(Mg_0.5Sn_0.5)O₃-xCaTiO₃Ceramic System

Abstract

The microwave dielectric properties of V2O5–doped (1-x)La(Mg0.5Sn0.5)O3-xCaTiO3 ceramic system prepared by the conventional solid-state method were investigated with a view to their potential for mobile communication. The X-ray diffraction peaks of (1-x)La(Mg0.5Sn0.5)O3-xCaTiO3 shifted to higher angles as x increased from 0.4 to 0.7. The X-ray diffraction patterns of the 0.4La(Mg0.5Sn0.5)O3–0.6CaTiO3 revealed no significant variation of phase with sintering temperatures. The average grain size of the 0.4La(Mg0.5Sn0.5)O3–0.6CaTiO3 increased from 3.1 to 8.6 μm as the sintering temperature increased from 1400 to 1550°C. The dielectric constant increased from 28.5 to 48.7 and the quality factor (Q × f) decreased from 46,800 to 22,900 GHz for (1-x)La(Mg0.5Sn0.5)O3-xCaTiO3 as x increased from 0.4 to 0.7 that were sintered at 1550°C for 4h. The average value of temperature coefficient of resonant frequency (τf ) increased from −56 to +46 ppm/°C as x increased from 0.4 to 0.7.