La1-yCayFe1-XCoXO3為離子-電子混和導體的陶瓷材料，是以LaFeO3當作基材進行共摻雜鈣與鈷所形成，可作為碳氫化合物燃料及高經濟價值化學品生產之催化劑，或是應用於前瞻性甲烷部分氧化技術，因為LaFeO3在低氧分壓環境下結構較穩定，早期就有研究用於部分甲烷轉換技術，近幾年有以鍶與鈷摻雜進行改質，當作燃料電池的陰極；或以鈣與鈷摻雜進行改質當作離子傳輸薄膜元件。
本研究選取與鑭(CN=12， =1.36Å)離子半徑相近的鈣(CN=12， =1.34Å)和鈷當作摻雜的離子，並改變摻雜的量觀察鈣與鈷摻雜對於LaFeO3的晶體結構及導電率的影響。氧化鑭與氧化鐵混合粉末於1200℃煆燒6小時後，形成近似正方相(斜方相)的鈣鈦礦結構。當A-site摻雜鈣的量為20%時，結構仍為近似正方相的鈣鈦礦結構，若繼續在B-site摻雜鈷從20%~60%結構維持近似正方相的鈣鈦礦結構，鈷摻雜量達80%時，煆燒後試樣結構由近似正方相變成菱方相的鈣鈦礦結構。
具鈣鈦礦結構的氧化物LaFeO3在空氣下800℃的導電率只有0.033S/cm，因此以摻雜鈣與鈷的方式提升導電性質，La0.8Ca0.2FeO3在800℃的導電率為90.63 S/cm ，再隨著鈷的添加量為20%~80%時，導電率皆隨鈷添加量與溫度增加而提升，La0.8Ca0.2CoO3在500℃導電率則會下降。
La0.8Ca0.2Fe1-XCoXO3(X=0~0.4)在氫氣還原氣氛下，會分解成氧化鑭、金屬鐵與金屬鈷，結構不穩定，導電率迅速衰退；在甲烷氣氛下時，La0.8Ca0.2Fe0.8Co0.2O3有較高的導電率約20S/cm。添加穩定元素鉻改善鑭鈣鐵鈷氧化物結構穩定性，在氫氣下La0.8Ca0.2Fe0.8Co0.16 Cr0.04O3比La0.8Ca0.2Fe0.8Co0.1Cr0.1O3有較好的導電率4.33S/cm，鉻的量增加效果反而不好。添加穩定元素鎂也能改善鑭鈣鐵鈷氧化物結構穩定性，在氫氣下La0.8Ca0.2Fe0.8Co0.1Mg0.1O3的導電率為6.2S/cm 比La0.8Ca0.2Fe0.8Co0.16 Mg0.04O3的導電率3.6S/cm高，是由於二價鎂是很難變價，所以穩定性會提升。

La1-yCayFe1-XCoXO3 is the ceramic material of mixed ionic and electronic conductors. LaFeO3 is chosen as the baseline material with calcium substitution for the lanthanum site and cobalt on the iron site in order to form La1-yCayFe1-XCoXO3. It can be used as membrane of partial oxidation of hydrocarbon fuel or high-valued chemical production. Because LaFeO3 has the stable structure in low partial pressure of oxygen, it has been used for partial oxidation reaction. Recently, Sr and Co-doped lanthanum iron oxide have been used as cathode of SOFC or Ca and ion transport membrane .
In this study, the calcium ion was selected to substitute lanthanum ion due to the similarity in ionic radius and cobalt ion was selected to substitute for iron ion. The addition of calcium ion and cobalt ion were varied to observe the influence on crystal structure and conductivity. The powder mixture of lanthanum oxide and iron oxide were calcined at 1200oC for 6h. The crystal structure of LaFeO3 showed orthorhombic structure which was confirmed by XRD analysis. The additive amount of calcium ion substituted A-site ion was 20% the crystal structure still formed orthorhombic structure. In addition, cobalt ion doping of B-site from 20% to 60% the crystal structure maintained orthorhombic structure . With increasing amount of cobalt doping up to 80% the crystal structure changed from orthorhombic to rhombohedral structure .
The conductivity of pure lanthanum iron oxide with perovskite structure was only 0.033S/cm at 800℃ in air. LaFeO3 was considered to be an insulator due to its low conductivity mentioned above. The common method of increasing conductivity was by calcium and cobalt ion doping. The conductivity of La0.8Ca0.2FeO3 at 800℃ in air was measured to be 90.63/cm. With the additive amount of cobalt ion from 20% to 80%, conductivity would be raising with increasing cobalt and temperature. The conductivity of La0.8Ca0.2CoO3 would decrease after 500℃.
In hydrogen reducing atmosphere, La0.8Ca0.2Fe1-XCoXO3(X=0~0.4) would decompose to be La2O3,metallic iron and metallic cobalt.The conductivity decreased rapidly. In methane atmosphere , La0.8Ca0.2Fe0.8Co0.2O3 had the higher conductivity than others. The structure stability of LCFC oxide may be improved by adding stable element chromium. Under the hydrogen reducing atmosphere, La0.8Ca0.2Fe0.8Co0.16Cr0.04O3 possessed better conductivity 4.33S/cm than La0.8Ca0.2Fe0.8Co0.1Cr0.1O3.The structure stability of LCFC oxide may be also improved by adding stable element magnesium. Under hydrogen atmosphere, La0.8Ca0.2Fe0.8Co0.1Mg0.1O3 possessed conductivity of 6.2S/cm which is higher than La0.8Ca0.2Fe0.8Co0.16Mg0.04O3 (3.6S/cm).

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