Difference in composition on the dielectric properties and microstructure of X8R BaTiO3 dielectric ceramics
| Autor: | Guan-Yu Zhu, 朱冠宇 |
|---|---|
| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 94 Commercial ceramic capacitors for application, can be briefly classified into Y5V, Z5U, X7R for EIA. Especially, it is the severest for X7R specification. The high temperature capacitor, X8R is made for automotive applications and other high temperature working environment. In this research, the grain growth of BaTiO3 occurred and no obvious concentration gradient of the dopants between the grain and grain boundary was observed for the sample added with a small amount of BaCO3. The ε-T curves demonstrated a obvious Tc peak. However, in the case of the samples added with the higher amount of BaCO3, the concentration gradient of the dopants between the grain and grain boundary was observed, which resulted in flattening of temperature coefficient of capacitance curve and satisfaction the X8R requirements. In this system, the mechanism of the stable temperature-capacitance characteristics may be resulted from the higher concentration of dopants per unit volume in the outer grain and the composition fluctuation. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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