烧结温度对YBCO陶瓷常温物理性能的影响

Effect of Sintering Temperature on Physical Properties of YBCO Ceramics at Room Temperature

采用固相烧结法制备YBa2Cu3O7-x（YBCO）陶瓷，研究其在常温下电导率特性及烧结温度对电导率和热膨胀系数的影响。研究结果表明，YBazCu3O7-x相形成的温度为930℃、940℃烧结的YBCO陶瓷电导率最佳（达到9．742×10^5S／m），电导率具有随环境温度的变化呈正温度系数特点；烧结温度越高，电导率的环境热稳定性越好，烧结温度为950℃时，电导率基本不随环境温度变化而变化。不同烧结温度制备的YBCO陶瓷，热膨胀系数基本一致（为13．60～14．06μK^-1），与铁素体不锈钢接近。

YBa2 Cu3O7-x. （YBCO） ceramics were prepared by conventional solid state method. Conductivity was measured at room temperature,the effect of sintering temperature on conductivity and coefficient of thermal expansion were studied. The results showed that the YBa2Cu3OT-x grains were mainly formed at 930 ℃. The highest conductivity （9. 742）〈 10^5 S/m） at room temperature of YBCO ceramics appeared when the sintering temperature was 940 ℃. Conductivity increased with the increase of environment temperature. The higher was the sintering temperature; the better was the thermal stability of the conductivity. When the sintering temperature reached 950 ~C, the conductivity hardly changed with the environment temperature. The coefficient of thermal expansion of YBCO ceramics sintered at different temperature was almost the same, about 13.60-14.06μK^-1 , approximating to ferritic stainless steel.