本論文主要以BaTiO3-Bi1/2Na1/2TiO3(BBNT)系統，進行低介電溫度變化材料的研究。在實驗中，先歸納出BBNT材料的基本性質及MgO與Y2O3共同添加的影響：BBNT材料的燒結溫度會隨著BNT在材料中所佔比例的增加有下降的趨勢。其介電常數也會下降，居禮溫度會往高溫區移動。MgO添加會造成居禮溫度往低溫移動的效果，Y2O3的添加會造成試片的致密性降低，燒結所需溫度提高。之後，我們改採用奈米尺寸鈦酸鋇粉末(nano BaTiO3)，添加燒結助劑Ba0.6Ca0.4SiO3(BCSO)，並以微波燒結(microwave sintering)。試片成分為(BaTiO3)0.925-(Bi1/2Na1/2TiO3)0.075 + MgO 2 mol% + Y2O3 1～1.5 mol% + BCSO 3 mol%，在1050℃，1～2小時的微波燒結下。可以得到小晶粒尺寸(約0.5μm)的微觀結構及平坦的介電隨溫度變化曲線。 In this thesis, we study the less temperature-dependence dielectric constant material by BaTiO3-Bi1/2Na1/2TiO3(BBNT) system. And conclude the basic properties of BBNT material and the inference of MgO and Y2O3: the sintering temperature of BBNT declines while the proportion of BNT increases. The dielectric constant of BBNT also decreases and its Curie peak shifts toward higher temperature. The effect of MgO shifts Curie peak toward lower temperature area. The effect of Y2O3 not only decreases the density of the bulk, but raises its sintering temperature requirement. Then we uses nano-size BaTiO3 powder. By adding sintering accelerant Ba0.6Ca0.4SiO3(BCSO) and applies microwave sintering, the content of the bulk consists of (BaTiO3)0.925-(Bi1/2Na1/2TiO3)0.075 + MgO 2 mol% + Y2O3 1~1.5 mol% + BCSO 3mol%. At 1050, and ℃microwave sintering for 1-2 hours, we get smaller grain size microstructure (about 0.5μm) and flatter curve of temperature-dependence dielectric constant.
