Effect of Additives on Microwave Characteristics and Electrical Properties of Bi2O3-ZnO-Nb2O5 Ceramics
|Keywords:||微波;陶瓷;鉍鋅鈮;添加劑;燒結;介電常數;品質因子;助熔劑;Microwav;Ceramics;Bi2O3-ZnO-Nb2O5;Additives;sintering;dielectric constant;Quality factor;flux|
|Abstract:||本實驗在於研究低溫燒結陶瓷-BZN（Bi2O3-ZnO-Nb2O5）系統的微波特性。配合微波通訊元件所需的積層結構開發，為了與低導電損失之純銀Ag內電極匹配，需具有約在950℃左右的燒結溫度的微波陶瓷系統，故對低溫燒結陶瓷系統BZN進行研究。經研究發現Bi2(Zn1/3Nb2/3)2O7這一個組成其燒結溫度950~1000℃，介電常數ε：70，品質因子Q約1200。在氧化物及結構化合物的添加中，發現僅少量的添加對BZN系統的微波特性略有改善，若添加量一提高則皆破壞其性質。在添加燒結促進劑方面發現添加BaO -2.5 CuO可以降低燒結溫度約50℃~100℃，而添加 0.85CuO-0.15MoO3則可以降低溫度100℃~ 150℃之間。另外利用MOD法對BZN組成的薄膜，有初步的研究。|
The development in microwave-communication devices tends toward multilayer integrated structure, in which Ag inner electrode with low conducting loss has to be used. Therefore, in the research, the Bi2O3-ZnO-Nb2O5 (BZN) ceramic system, having low sintering temperature, was chose as a basis to study the physical characteristics, phase transformation behavior and microwave properties. As we found, the dielectric constant at 3 GHz and Quality factor of BZN ceramics when sintered at 950~1000°C, are around 70 and 1200, respectively. In order to study the addition of metal oxides on the microwave properties and sintering behavior of BZN ceramics, a variety of metal oxides with different ion size and valence were used. As the added amount was below 2 wt %, a little improvement in microwave characteristics was observed. However, as the doped amount increased, the microwave electrical properties were degraded. On the other hand, in order to decrease the sintering temperature further, both BaO-2.5CuO and 0.85CuO-0.15MoO3 flux systems were used. It was found that the sintering temperature of BZN ceramics can be decreased from 950°C to 850°C; the lower sintering temperature can be completely satisfied for the use of Ag electrode in the multilayer structure. In addition, the BZN thin films using MOD process was also briefly studied.
|Appears in Collections:||Thesis|