偏壓對加釔的鈦酸鍶鋇陶瓷及鈦酸鍶鋇/矽橡膠複合物介電性質的影響

Abstract

本論文的討論重點著重於外加偏壓對摻雜釔之鈦酸鍶鋇陶瓷體與鈦酸鍶 鋇/ 矽橡膠複合物介電特性的影響。經電性分析顯示，摻雜釔於鈦酸鍶鋇 陶瓷體在順電區其介電常數變化率隨外加偏壓會增加。定義介電可調性為 鈦酸鍶鋇陶瓷體在順電區介電常數隨外加偏壓而變化比例。選擇0.1%的釔 摻雜濃度將獲得較大之介電可調性，又改變私被比例可決定居里溫度。將 鈦酸鍶鋇陶瓷體混以不同含量的矽橡膠聚合物可形成一二元複合體。經介 電量測，顯示其介電常數大幅降低，推斷此二元相以串聯模式連通。若將 矽橡膠聚合物填於鈦酸鍶鋇陶瓷體之間，將使此二元複合體以並聯模式連 通，如此可獲得較大之介電可調性。 The dielectric behaviour with applied DC bias of Y-doped Ba1- xSrxTiO3Ceramic and Ba1-xSrxTiO3/Silicon rubber has been analyzed in the theme. Doping Y into Ba1-xSrxTiO3 ceramic results in an improvement of dielectric constant change percentage with applied DC bias. Thedielectric tunability which is defined as the change percentage of thedielectric constant for Ba1-xSrxTiO3 ceramic with applied DC bias in theparaelectric state. Selecting of 0.1% Y-dopant concentration enhance the dielectric tunability. Specific Sr/Ba molar fraction decides the CurieTemperature. A composite mixing Ba0.8Sr0.2TiO3 powder with different amount of silicon rubber polymer was fabricated. Studying the dielectric behaviourof this elastic composite, a tremendous reduction of dielectric constantsuggests that these two phases are mixed in series connectivity. Theother case of parallel connectivity is also fabricated by corresponding thepolymer around the bulk sample. In this case, the dielectric tunability isenhanced comparing to that of series case.