熱電材料透過溫差即可將熱能與電能轉換，為一種受到期待的功能材料。熱電材料在溫差發電及熱電致冷方面都具有廣泛的應用價值，其中陶瓷熱電材料具有成本低廉、無毒、無污染等之優點，是深受期待的材料。而陶瓷材料中之鈦酸鍶是功能性非常多元的材料，具有介電常數高、Seebeck係數高、熱穩定性好等之優點，是被期待的熱電材料之一。
稀土元素的摻雜為提升鈦酸鍶熱電性質的常見手段，其中以鑭摻雜之鈦酸鍶在前人的研究中具有最佳熱電性質。此外，鍶與鈦的計量調整為改善鈦酸鍶熱電性質的一個新方向，當鍶不足時材料內會產生鍶空缺，進而影響鈦酸鍶的熱電性質。
因此，本研究以鍶不足量的摻鑭鈦酸鍶為研究材料，實驗以固相反應法合成不同粉體，將粉體成型後於氬氫還原氣氛(Ar-5% H2)中以1450 ℃燒結4小時成為Sr0.92-xLa0.08TiO3-δ (x = 0-0.15) 塊材，並檢討鍶不足塊材之結晶相、微結構、電傳導與熱傳導特性及熱電性質的影響。
結晶相及顯微結構方面，鍶不足有助於晶粒的成長，當鍶不足≥ 0.1 at.%時，摻鑭鈦酸鍶中會出現均勻散佈之奈米TiOx第二相的顆粒，其顆粒粒徑小於100 nm，且過多的鍶不足會影響鈦酸鍶之結晶度。
電傳導特性方面，隨著鍶不足的增加，電傳導率呈現先增後減的趨勢，顯示微量鍶不足有助於電傳導率之提升，但過量的當鍶不足會出現TiOx第二相的顆粒，造成載子被散射使電傳導率無法進一步再提升。x = 0.05試樣具有最高的功率因子(Power factor)，其值約為1.7 mW/m-K2。
熱傳導率方面，鍶不足形成之奈米TiOx第二相顆粒，能有效的散射聲子，來達到熱傳導率的降低，故試樣x = 0.15具有最低之熱傳導率。綜合各項熱電性質後計算試樣之ZT值，結果顯示鍶不足之諸試樣其ZT值均高於未有鍶不足之試樣，表示鍶不足為提升摻鑭鈦酸鍶熱電性質的有效策略。x = 0.05試樣具有最高ZT值，在673 K時約為0.17，相較於x = 0.00之試樣增加了70 %。

In this study, nonstoichiometric Sr0.92-xLa0.08TiO3-δ (x = 0−0.15) bulks were prepared to assess the impact of Sr-deficiency on the thermoelectric performance of La-doped strontium. La-doped SrTiO3 powders prepared by 2-step calcination with intermediate regrinding where sintered at 1450 °C for 4 hours in a 5% H2/Ar. The crystal structure and microstructure were confirmed by XRD and SEM, respectively. Separation of a minor secondary Ti-rich phase particles were observed for the x ≥ 0.1 samples, as a compensation for a significant deviation in the A/B site ratio from the stoichiometric value. Thermoelectric properties of bulk samples were investigated over the temperature range of 25°C to 400°C. Sr-deficiency was found to have a noticeable effect on the electrical conductivity, with less significant alteration of Seebeck coefficient. High power factor observed in composition where an appropriate Sr-deficiency was attained. The existence of second phase particles did result in a larger decrease in the thermal conductivity. Consequently, Sr0.87La0.08TiO3 showed the highest the highest figure of merit (ZT)value of ~0.17 at 673 K.

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