Bi_(1.7)Pb_(0.3)Sr_2Ca_2Cu_3O_x超导体中热相变与纳米尺度结构块的研究

Investigation of thermal phase transition within crystal structural blocks in nanometer size in superconductor Bi_(1.7)Pb_(0.3)Sr_2Ca_2Cu_3O_x

用变温X 射线衍射仪、扫描量热分析仪和热重分析仪对精心制作的Bi1.7Pb0.3Sr2Ca2Cu3Ox超导样品从室温到熔点温度进行了分析.实验发现样品在此温度范围有两个热量和重量反常.分析表明:这两个反常与晶体结构中纳米尺度上两个不同的结构块———钙钛矿块和盐岩块有关,这对认识高温超导体的结构与性能关系有重要作用.

Wellprepared samples of superconductor Bi1.7Pb0.3Sr2Ca2Cu3Ox are analyzed in the range from roomtemperature to melting point with temperaturevarying Xray diffractometer, differential scanning calorimetry, and thermo gravimeter. It is found that there are both the thermal and gravitational abnormality with the samples in this temperature range. The analysis shows that these two abnormalities are related to two different crystal structural blocks in nanometer size within the crystallineperovskite and rocksalt, and this is significant for having acquaintance with the relationship between the structures and characteristics of hightemperature superconductor.