Fabrications of the lead-free (Na0.5K0.5)NbO3-SrTiO3 piezoelectric ceramics and their applications on the Surface Acoustic Wave (SAW) Filters
| Autor: | Yi-Peng Wong, 翁逸鵬 |
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| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 Recently, due to the raise of environmental sense many chemical substances will be inhibited. PZT is the piezoelectric material which is most often used, but the substituted development is not easy. Therefore, develops of the lead-free materials is the present tendency. Potassium sodium niobate (Na1-xKxNbO3) is a ferroelectric material of perovskite structure. The good piezoelectric characteristics makes it to be one of popular candidates of lead-free piezoelectric material. In this report, we fabricate ceramics with the soild state reaction method and investigate the effect of Strontium Titanate (SrTiO3) dopants. The results showed that the SrTiO3 doped with 0.5 mol% has great electromechanical planar and thickness coupling coefficients of kp = 38% and kt = 42%. By measurement of P-E curve, the remanent polarization and coercive field are 12.4 KV/cm and 11.7 μC/cm2, respectively. In this report, we successful fabricate the surface acoustic wave filters on the lead-free NKN substances. The phase velocity, temperature coefficient of frequency (TCF) and mechanical electrical coupling of factor K2 are measured. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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