YBaCo_2O_(5+δ)混合导体的电学性能研究

Study on the Electronic Properties of YBaCo_2O_(5+δ) Mixed Conductor

采用柠檬酸盐法制备了纯相YBaCo2O5+δ粉体。西贝克系数测量结果表明,在200℃～800℃内YBaCo2O5+δ的载流子类型为p型。利用间接碘量法测定了YBaCo2O5+δ样品中Co离子的平均价态及氧非化学计量数,实验发现,淬火温度为300℃时,YBaCo2O5+δ中Co离子的平均价态和氧非化学计量数最大。利用四端子法测量其在空气中不同温度下的电导率,得到电导率范围为30.99～45.04S.cm-1。

Pure YBaCo2O5＋δ was synthesised by citric acid method.Through seebeck coefficients of measurement,shows that YBaCo2O5＋δ is a p-type conductor when the temperature is 200~800℃.The average valence of Co and the oxygen nonstoichiometry of YBaCo2O5＋δ were studied by means of indirect iodometric titration,it was found when the temperature is at 300℃,the average valence of cobalt ions and oxygen nonstoichiometr in YBaCo2O5＋δ are the largest.Measured conductivity using four-pole method at different temperatures in air,obtain its conductivity range is 30.99~45.04 S.cm-1.