(江蘇科技大學(xué) 數(shù)理學(xué)院， 鎮(zhèn)江 212003)
摘 要: 采用固相反應(yīng)法合成了具有菱方鈣鈦礦結(jié)構(gòu)的La0.9Sr0.1Al0.9Mg0.1O3-y(LSAM9191)， 并使用直流四極法對(duì)其電導(dǎo)率與溫度(600～1 000 ℃)和氧分壓(10-1~105 Pa)的關(guān)系進(jìn)行了測(cè)量。 通過(guò)摻雜， 樣品的離子電導(dǎo)率得到了顯著提高， 在900 ℃時(shí)LSAM9191的氧離子電導(dǎo)率為8.6×10-3 S/cm， 離子電導(dǎo)活化能為1.04 eV。 從電導(dǎo)率隨溫度和氧分壓的變化關(guān)系分析可知， LSAM9191在低氧分壓(＜10-4 Pa)下是一個(gè)純氧離子導(dǎo)體， 而在高氧分壓(＞10-4 Pa)下則是一個(gè)混合離子導(dǎo)體。 隨著溫度的升高， 其氧離子遷移數(shù)和離子導(dǎo)電區(qū)域都輕微增大。 LSAM9191在高溫和低氧分壓環(huán)境下是一個(gè)性能優(yōu)良的氧離子導(dǎo)電材料。
關(guān)鍵字: 混合離子導(dǎo)體； 氧離子導(dǎo)體； 電導(dǎo)率； 鋁酸鑭
（ School of Mathematics and Physics, Jiangsu University of Science and Technology, Zhenjiang 212003, China）
Abstract: La0.9Sr0.1Al0.9Mg0.1O3-y(LSAM9191) was synthesized by using a standard solid state reaction method. The electrical property of LSAM9191 was measured using the DC four-probe method as a function of temperature(600-1 000 ℃) and oxygen partial pressure(10-1-105 Pa). XRD results show that LSAM9191 is rhombohedral perovskite structure. Doping of Sr and Mg increases the ionic conductivity significantly. Oxide ion conductivity of LSAM9191 is 8.6×10-3 S/cm at 900 ℃, the activation energy is 1.04 eV.The analysis of the oxygen partial pressure (p(O2)) and temperature dependence of electrical conductivity shows that LSAM9191 is an oxygen ion conductor below 10-4 Pa and a mixed conductor above 10-4 Pa at 900 ℃. With increasing temperature, the ionic transference number and the ionic conduction region slightly increase. Thus, LSAM9191 is a promising material as an oxygen ion conductor at high temperature in low p(O2), it may possibly be used for monitoring oxygen activities in molten steel.
Key words: mixed conductor； oxygen ion conductor； electrical conductivity； LaAlO3
