Study on the Electronic Properties of YBaCo₂O_5+δ Mixed Conductor

Pure YBaCo₂O_5+δ was synthesised by citric acid method.Through seebeck coefficients of measurement,shows that YBaCo₂O_5+δ is a p-type conductor when the temperature is 200~800℃.The average valence of Co and the oxygen nonstoichiometry of YBaCo₂O_5+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 YBaCo₂O_5+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.