Microwave dielectric properties of (1-x)La(Mg0.5Sn0.5)O3-x(Sr0.8Ca0.2)3Ti2O7 ceramic system with a near zero temperature coefficient of resonant frequency

✍ Scribed by Yih-Chien Chen; Yen-Nien Wang; Kai-Hao Chen

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 185 KB
• Volume: 45
• Category: Article
• ISSN: 0232-1300
• DOI: 10.1002/crat.201000073

✦ Synopsis

In this study, the microwave dielectric properties of (1-x)La(Mg 0.5 Sn 0.5 )O 3 -x(Sr 0.8 Ca 0.2 ) 3 Ti 2 O 7 ceramic system prepared by the conventional solid-state method have been investigated for application in mobile communication. It was found that the diffraction peaks of (1-x)La(Mg 0.5 Sn 0.5 )O 3 -x(Sr 0.8 Ca 0.2 ) 3 Ti 2 O 7 ceramic system shift to higher angles as x increases from 0.2 to 0.4. It was also found that the X-ray diffraction patterns of the 0.8La(Mg 0.5 Sn 0.5 )O 3 -0.2(Sr 0.8 Ca 0.2 ) 3 Ti 2 O 7 ceramics exhibited no significant phase difference at different sintering temperatures. The average grain size of the (1-x)La(Mg 0.5 Sn 0.5 )O 3 -x(Sr 0.8 Ca 0.2 ) 3 Ti 2 O 7 ceramic system decreased from 6.4 to 4.3 µm as the value of x increased from 0.2 to 0.4 sintered at 1550 °C for 4 h. The dielectric constant increased from 26.6 to 35.9 and the quality factor (Q×f) decreased from 31,600 to 23,300 GHz for (1-x)La(Mg 0.5 Sn 0.5 )O 3 -x(Sr 0.8 Ca 0.2 ) 3 Ti 2 O 7 ceramic system as the x value increases from 0.2 to 0.4 sintered at 1550 °C for 4 h. The average value of temperature coefficient of resonant frequency (τ f ) increased from -18 to +8 ppm/ K as the x value increases from 0.2 to 0.4.