CAJ | 학술논문

采用软化学法制备了YBa2Cu3O7-x(YBCO)纳米单晶，并与利用传统固相法制备出YBCO陶瓷粉末作对比。性能测试表明：YBCO纳米单晶的晶体结构为具有高结晶度和良好单相性的正交对称钙钛矿结构，其具有200 nm-500 nm的粒度尺寸和很好的单晶结构，其高温超导性具有超导转变温度低、转变温度区间宽、电阻大等性能，此外其还表现出了一定的室温铁磁性，这是由YBCO纳米单晶的小尺寸效应、相滑移机制、高表面离子缺陷浓度、特殊的单晶表面性质等引起的。
채용연화학법제비료YBa2Cu3O7-x(YBCO)납미단정，병여이용전통고상법제비출YBCO도자분말작대비。성능측시표명：YBCO납미단정적정체결구위구유고결정도화량호단상성적정교대칭개태광결구，기구유200 nm-500 nm적립도척촌화흔호적단정결구，기고온초도성구유초도전변온도저、전변온도구간관、전조대등성능，차외기환표현출료일정적실온철자성，저시유YBCO납미단정적소척촌효응、상활이궤제、고표면리자결함농도、특수적단정표면성질등인기적。
YBa2Cu3O7-x single crystal in nanosize was successfully synthesized via soft chemical method. A group of YBCO ceramic powders were also prepared by traditional solid reaction method for comparison. Results show that YBa2Cu3O7-x nanosize single crystal is of a single perovskite structure phase with an orthorhombic symmetry and high crystallinity. The TEM images show that its particle sizes are 200 nm-500 nm. Besides, it shows high temperature superconductivity with novel aspects, such as lower critical temperature, broader transition temperature area and higher resistance. Furthermore, unconventional room temperature ferromagnetism was also detected. Nanosize, phase slip mechanism, high ion-induced surface defect concentration and novel surface properties generated by the special structure of the nanosize single crystal were considered as the reasons.