The dielectric properties and the microstructures of LaAlO3 ceramics with CuO additions (0.25-1 wt%) have been investigated. The sintered LaAlO3 ceramics are characterized by X-ray diffraction spectra and scanning electron microscopy (SEM). The ceramic samples show that a dielectric constant (εr) of 19-22 and a Q × f value of 5000-48,000(at 9.7 GHz) can be obtained at low sintering temperatures of 1370-1460°C. The temperature coefficient of resonant frequency varies from -50 to -80 ppm/°C. At the level of 0.5 wt% and 1 wt% CuO additions, low Q × f value of the LaAlO3 ceramics is owing to the formation of the second phase LaAl11O18. With CuO addition, an 100-200°C reduction in sintering temperature can be achieved for the LaAlO3 ceramics.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering