Sr_(0.5)Sm_(0.5)CoO_3超细陶瓷粉体的制备与性能

PREPARATION AND CHARACTERIZATIONS OF ULTRAFINE Sr_(0.5)Sm_(0.5)CoO_3 CERAMIC POWDER

采用低温燃烧法和共沉淀法制备了Sr0.5Sm0.5CoO3(SSC)超细陶瓷粉体。应用综合热分析、X射线衍射仪、扫描电子显微镜和元素分析仪等对陶瓷粉体的组成、结构和形貌进行了表征。结果表明:采用低温燃烧法制备的SSC为近似球形、粒径小于200nm的超细钙钛矿结构的粉体;用共沉淀法制备了粒径约为500nm,具有钙钛矿结构的SSC超细粉体。低温燃烧法制备的SSC粉体在1150℃烧结致密,共沉淀法制备的SSC粉体在1200℃烧结致密。低温燃烧法和共沉淀法制备的SSC陶瓷膜在空气流速为1.12×10-4mol/s,氦气流速为6.70×10-5mol/s,900℃的条件下,透氧速率分别为4.61×10-7mol/(s·cm2)和4.46×10-7mol/(s·cm2)。

Ultrafine Sr0.5Sm0.5CoO3 （SSC） ceramic powders with homogeneous composition were prepared via a low temperature combustion process and a coprecipitation process,respectively.The resultant SSC powders were characterized by X-ray diffraction,scanning electron microscope and energy dispersive spectroscope.The results show that the SSC particles obtained by the low-temperature combustion are near spherical and the particle size is less than 200 nm;and the particles obtained by the coprecipitation process appear a perovskite structure and the average size is 500 nm.The pressed SSC powders obtained from the low-temperature combustion and the coprecipitation process can be sintered in air at 1150 ℃ and 1200 ℃ intothe dense pellet samples,respectively.The oxygen permeation rates through the SSC dense films obtained by the low-temperature combustion and the coprecipitation process are approximately 4.61×10-7 and 4.46×10-7 mol/（s·cm2） at 900 ℃ respectively,when the flow rates of air and He are 1.12×10-4 mol/s and 1.70×10-5 mol/s,respectively.