金属纳米晶体超导温度的热力学研究
毕业论文关键词:纳米材料；超导温度；临界转变温度；热力学模型
Abstract In recent years, nano-sized materials science research and application of moderntechnology has attracted great interest to scientists. When the material is reduced to thenanometer scale size range class, optical, electrical, magnetic and thermodynamicproperties are different from the chunk size, and the difference is not small. This is becausethe small size of nano materials, surface / volume ratio, surface atomic aggregationproperties of surface atoms caused by differences in the coordination of defects. In all theproperties mentioned above, the thermodynamic properties of the nanocrystals isparticularly important. The method described by the theory of thermodynamic properties isa very great and meaningful work, not only to deepen our understanding of the nature ofthe nanocrystals can also guide the preparation of test operation and expand theirapplications in different fields.Based on a size-dependent cohesive energy model and combined with thecorresponding thermodynamic theory, the initial establishment of the superconductingmetal nanocrystals thermodynamic model to describe the critical transition temperatureTc(D) of the material as the variation of the grain size D. In this model, the criticaltransition temperature of superconducting nanocrystals is dependent on the size, Tc(D)depends on the D and the critical conditions. All the predicted results of the model areconsistent with the experimental results for a variety of free nanoparticles, nanowires orfilms. It can be seen that the establishment of the model is an indispensable bridge betweentheory and experiment.
Keywords: nanocrystalline materials; superconducting temperature ;critical transitiontemperature ;Thermodynamic model
目录
第一章 绪论 1
1.1选题的目的及意义. 1
1.1.1 选题的目的.. 1
1.1.2 选题的意义.. 1
1.1.3 本课题主要研究方法 2
1.2 研究背景2
1.2.1 纳米材料的结构与特性. 2
1.2.2 纳米材料的合成方法.. 4
1.2.3 纳米材料的应用..6
1.2.4 纳米材料基本特征.8
1.3 超导温度10
1.3.1 超导温度的概念10
1.3.2 超导材料的研究现状及应用10
1.3.3 超导材料的前景展望 11
1.4 本课题主要工作内容11
第二章 金属纳米晶体超导温度的热力学研究. 12
2.1引言 12
2.2 理论模型13
2.3 结果与讨论..14
2.4 小结.. 17
总结.18
致谢 19
参考文献.20