本文選題：磁控濺射　切入點：GDC薄膜　出處：《昆明理工大學》2017年碩士論文　論文類型：學位論文

【摘要】：相比傳統(tǒng)的氧離子導體固態(tài)電解質(zhì)Y摻雜的穩(wěn)定Zr02(YSZ),Gd摻雜的Ce02(GDC)因其在中溫條件下具有更高的電導率而被廣泛研究。為了滿足電解質(zhì)材料薄膜化、中溫化的發(fā)展趨勢,對GDC電解質(zhì)的制備工藝以及電導性能的研究顯得越來越重要。本論文采用反應(yīng)直流磁控濺射法在單晶A1203基片上制備了 GDC薄膜,XRD物相分析結(jié)果表明磁控濺射法制備的GDC薄膜具有立方螢石結(jié)構(gòu),沿(111)面擇優(yōu)生長。SEM形貌觀察結(jié)果顯示GDC薄膜具有典型的柱狀晶結(jié)構(gòu),薄膜與基片結(jié)合力良好。TEM分析結(jié)果表明不同退火溫度下GDC薄膜晶粒尺寸在10 nm到100 nm之間。采用溶膠-凝膠法制備了含F(xiàn)e和Si元素的溶膠,將溶膠涂覆在GDC薄膜表面,再通過熱擴散工藝將Fe元素和Si元素摻雜到晶界處,對GDC薄膜的能譜分析表明GDC薄膜的晶界處含有硅質(zhì)相,而摻雜的Fe元素能夠改變晶界處硅質(zhì)相的潤濕性,使晶界處的硅質(zhì)相收縮在三個晶粒交界處。對GDC薄膜的電導率測試研究表明,擴散摻雜Fe元素能夠明顯提高薄膜的電導率,在800℃退火條件下提高了數(shù)倍左右,晶體的電導激活能沒有改變。當給薄膜摻雜Si元素后,測試其電導率并且與制備態(tài)和摻雜Fe元素的樣品作對比,摻雜Si元素的樣品電導率明顯降低,而Fe元素的摻雜則可以明顯提高其電導率,這進一步說明了摻雜Fe元素可以改變晶界處硅質(zhì)相的潤濕性,使晶界處的硅質(zhì)相收縮在三個晶粒交界處,從而提高GDC薄膜的電導率。由于Ce02在還原氣氛或者低氧分壓條件下具有一定的電子電導,本論文通過研究氧分壓與GDC薄膜電導率的關(guān)系,從實驗方面驗證了氧分壓對GDC薄膜的電導率有一定的影響。通過控制不同的退火溫度,本論文測試了在未退火(常溫25 ℃)、500 ℃、800 ℃及1200 ℃退火溫度下樣品的晶粒尺寸以及微觀形貌,通過研究它們的電學性能建立了晶粒尺寸大小與電導率的關(guān)系,從實驗結(jié)果來看800 ℃是很合適的退火溫度。
[Abstract]:Compared with the conventional oxygen ion conductor solid electrolyte Y doped stable Zr02 / YSZ / Gd doped ce 02N GDCs have been widely studied because of their high conductivity at medium temperature. In order to meet the development trend of electrolyte thin film and intermediate temperature, It is more and more important to study the preparation process and conductivity of GDC electrolyte. In this thesis, GDC thin films were prepared on single crystal A1203 substrate by reactive DC magnetron sputtering. The prepared GDC thin films have cubic fluorite structure, The results of preferential growth along the surface of GDC show that GDC thin films have typical columnar crystal structure. The results of TEM analysis showed that the grain size of GDC thin films varied from 10 nm to 100 nm at different annealing temperatures. The sol containing Fe and Si was prepared by sol-gel method, and the sol was coated on the surface of GDC films. Then Fe and Si elements are doped into grain boundaries by thermal diffusion process. The energy spectrum analysis of GDC films shows that there are silicon phases in the grain boundaries of GDC films, and the wettability of silicon phases at grain boundaries can be changed by doping Fe elements. The silicon phase at grain boundary shrinks at the junction of three grains. The conductivity measurement of GDC thin film shows that the diffusion doped Fe element can obviously improve the conductivity of the film, and it can be increased several times at 800 鈩，

本文編號：1604082