TiO2陶瓷體可藉由添加適當之添加劑及製程改善，使其具有良好的介電與變阻效應，本論文主要研究不同的結晶相粉末、燒結溫度與冷卻方式對TiO2陶瓷體變阻性質之影響。
　　相較於傳統固態反應法，利用化學共沉法制備的粉末因為顆粒較細，故具有較佳的燒結活性，故本研究利用化學共沉法製備摻Ba2+、Bi3+、Nb5+之TiO2粉末，嘗試在較低溫（＜1200℃）製備TiO2變阻器。
　　不同的煆燒溫度可以得到不同的結晶相，而不同的結晶相會因為具有不同特性而造成燒結後陶瓷體的電性差異，由實驗結果，起始粉末為銳鈦礦相的樣品其變阻特性較銳鈦礦與金紅石混合相、金紅石相佳。本論文亦研究了不同的冷卻方式（淬冷、爐冷）對微結構與變阻性質的影響，淬冷之樣品會在晶界處析出Ba2Ti9O20相及極少量之細晶粒Bi2Ti4O11相；而爐冷方式冷卻的樣品因為其二次相Bi2Ti4O11在冷卻過程中會聚集且長大為大顆粒的二次相晶粒而使得變阻性質劣化，故淬冷樣品的變阻特性較爐冷佳。
　　整體來說，製程條件為起始粉末銳鈦礦相、較高溫燒結、淬冷方式冷卻的樣品有最佳的變阻性質，其α值為2.91；Eb值為146.26 V/mm。

　In this study, the TiO2 varistor doped with Ba2+、Bi3+、Nb5+ were prepared using co-precipitation method in order to decrease the sintering temperature to below 1200℃. The effects of the crystalline phases of precursors, sintering temperatures and cooling ways on the microstructures and electrical properties of (Ba,Bi,Nb)-added TiO2 ceramics were investigated.
　The observed results can be described as follows:
1. The samples sintered at higher sintering temperature possessed better varistor properties.
2. The sintered compacts made from anatase powder possessed the best varistor property by comparing with other two crystallite phase precursors, anatase + rutile and rutile.
3. Compared with the influences of two cooling ways, quenching in air and furnace cooling, Ba2Ti9O20 and Bi2Ti4O11 phases segregated on grain boundaries and triple junctions for quenched samples. For furnace cooling samples, Bi2Ti4O11 crystallites were observed to coarsen during cooling, which resulted in degradation of varistor properties.
　In conclusion, the TiO2 ceramics made from anatase precursor, sintered at higher temperature, and quenched in air can obtain the best varistor properties, α is 2.91 and Eb is 146.26 V/mm.

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