标题: | 小分子嵌入高温超导体衍生物之化学合成与特性鉴定之研究 A Study on The Chemical Intercalation of High-Tc Superconductors With Small Molecules |
作者: | 胡欣 Hu Hsin 陈登铭 Chen Teng-Ming 应用化学系硕博士班 |
关键字: | 化学的 ; 嵌入反应 ; 高温超导体;Chemical ; Intercalation ; High-Tc Superconductors |
公开日期: | 1993 |
摘要: | 本研究之主旨在于探讨铋系铋-2212 高温超导体分别与小分子客体氨和平 面分子客体 pyridine 的嵌合化学及衍生物的基本特性鉴定. 本研究藉由 气体反应法, 真空封管法和溶液回流法等三种方法, 得到超导临界温度( Tc)为 93K 的氨嵌入产物与 Tc 为 90K 的 pyridine 产物.经由晶格常数 的估算可以推论出氨及 pyridine 的嵌入反应分别造成宿主晶格沿 c 轴 方向不同程度的增长. 经特性鉴定与分析, 可以证实氨及 pyridine 嵌 入所造成的部分电荷转移现象是超导临界温度值提升的主因. 在本研究中 探讨了嵌入反应所使用的反应方法, 并推论嵌入产物所可能的晶格结构, 以合理地解释在铋-2212 嵌入反应中所观察到的超导临界温度变化现象; 证实经由嵌入反应可以改变高温超导体的电子结构, 达到有效影响超导临 界温度的目的. The main purpose of this research is to investigate the intercalation chemistry of Bi-2212 superconductors with small moolecules and to characterize the intercalates derived from high-Tc Bi-2212 and ammonia or pyridine molecules. Intercalates have been prepared by employing gas-solid, evacuated seal-tube or solution-reflux type of reactions. On the Other hand, various degrees of the expansion in the crystallographic c-axis of the Bi-2212 have been observed in both ammonia- and pyridine- intercalated species based on the analysis of variations of the lattice constant. The enhancement of superconducting transition temperature (Tc) determined by electrical resistivity and magnetization measurements in both ammonia- and pyridine- intercalated species has been attributed to the partial charge transfer based on the characterization results. In this research we have explored the techniques employed in the intercalation reactions, deduced the possible structure of the intercalates, and rationalized the variation in superconductivity in the host. We have also demondtrated that chemcal intercalation is an effective route in systematic modification of electronicof high-Tc superconductors. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#NT820500015 http://hdl.handle.net/11536/58398 |
显示于类别: | Thesis |