隨著各國環保意識的高漲，使得許多含有對環境及人體健康有害元素及材料將會被逐步禁止使用，而對於壓電陶瓷材料來說，也必定會朝開發出更優良的無鉛壓電材料的方向去努力。
(Bi0.5Na0.5)TiO3為目前無鉛壓電材料中較具有潛力的材料系統，並且製程中不需倚賴特殊氣氛，而且不會有 Pb逸散問題，故本研究將以固態反應法合成具有 MPB (morphotropic phase boundary) 存在之 (1-x)(Bi0.5Na0.5)TiO3-x(Ba1-aSra)TiO3固溶系統，並針對 a=0.05及 0.3二系統中詳盡分析 x=0~0.12之晶體結構及基本電性質，以連結介電性質和晶體結構之關係。
經實驗結果可以確定以下幾點，第一，合成出 (1-x)(Bi0.5Na0.5)TiO3-x(Ba1-aSra)TiO3單一相存在的固溶系統，並得到相對密度達 98%以上之緻密燒結體。第二，詳盡說明本系統隨著成份變動使其晶體變化的過程，並經由 Rietveld Mothod計算得到其晶格常數、晶格體積及理論密度值，進而分析晶體結構中各離子的分布及偏移情形。第三， MPB成分可由容忍因子推算且印證，於 a=0.05系統落於 x=0.06；而 a=0.3系統將移至 x=0.08。第四，提出本系統極化後介電常數及壓電係數表現主要影響因素為氧八面體中陰陽離子偏移量的改變量及 MPB之存在。

With the raising of the environmental sense, some materials which contain harmful health elements and materials will be inhibited. For the piezoelectric materials, new lead-free piezoelectric materials with better electric properties will also be developed.
(Bi0.5Na0.5)TiO3 is a excellent candidate system in lead-free piezoelectric materials system at present because of its outstanding advantage in free control atmosphere and no lead pollution. In this research, the Ba2+ and Sr2+ were both doped into this composition system via solid state reaction to synthesize (1-x)(Bi0.5Na0.5)TiO3 - x(Ba1-aSra)TiO3 solid solution system. When a is 0.05 and 0.3, the crystal structure and electric properties of the two system were studied in detail. According to the changes of the crystal structure and electric properties which resulted from the composition variation of x equal 0 to 0.12 in this research.
The result show that：First, (1-x)(Bi0.5Na0.5)TiO3 - x(Ba1-aSra)TiO3 solid solution system could be synthesized successful in this research. And the relative density of sintered bulks of each composition could achieve 98% or over. Second, the phase transformation with composition variation of this system was showed in detail in this research. Besides, the cell parameters, cell volume, and theoretical density were also obtained after the Rietveld method calculation and get the displacement of atoms in the crystal structure. Third, the MPB could be calculated by tolerance factor and confirmed by the experiment result. The MPB region exists when a equal 0.05,x is 0.06 but a equal 0.3,x is 0.08. Fourth, presents the main factors which affect the dielectric properties after poling and piezoelectric coefficient are the modifiability of the displacement between cation and anion center in oxygen-octahedral structure and the existence of MPB.

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