Dielectric properties of CaTiO3-Ca(Mg1/3Nb2/3)O-3 ceramic system at microwave frequency

Citation
Cl. Huang et al., Dielectric properties of CaTiO3-Ca(Mg1/3Nb2/3)O-3 ceramic system at microwave frequency, JPN J A P 1, 39(12A), 2000, pp. 6608-6611
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Volume
39
Issue
12A
Year of publication
2000
Pages
6608 - 6611
Database
ISI
SICI code
0021-4922(200012)39:12A<6608:DPOCCS>2.0.ZU;2-Z
Abstract
The crystal structures and the microwave dielectric properties of the (1 - x)CaTiO3-xCa(Mg1/3Nb2/3)O-3 perovskite ceramic system have been investigate d. The (1 - x)CaTiO3-xCa(Mg1/3Nb2/3)O-3 solid solution exhibited orthorhomb ic crystal structures for all compositions. As the x value increases from 0 .2 to 0.8, the dielectric constant epsilon (r) decreases from 109 to 36 and the unloaded quality value Q x f increases from 8600 to 39000 (at 6.7 GHz) . The temperature coefficient of the resonant frequency (tau (f)) varies fr om 298 to -30 ppm/degreesC as the x value increases from 0.2 to 0.8. A new microwave dielectric material, 0.4CaTiO(3)-0.6Ca(Mg1/3Nb2/3)O-3, applicable in microwave devices is suggested and possesses the dielectric properties of a dielectric constant epsilon (r) similar to 54, a Q x f value similar t o 32000 (at 6.7 GHz) and a tau (f) value similar to 18 ppm/degreesC. Furthe r improvement of the tau (f) value is expected by adjusting the x value of( 1 - x)CaTiO3-xCa(Mg1/3Nb2/3)O-3 ceramics.