本論文包含兩部份的研究。第一部份使用穿隧電子顯微技術(STM)來研究鐵硒超導體薄膜的性質。我們使用雷射濺鍍技術，在氧亞鎂基板上成長了彼此夾著45度角的鐵硒碲薄膜，並利用STM發現其在靠近晶界處，鐵硒碲的超導能隙從1.78電子伏特變化到18.6電子伏特。因為在晶界處，相鄰兩晶塊的相互擠壓而產生相當大的應力，這隱含著在邊界處的應力會提升超導體的超導能隙。

在第二部份中，我們發展出能同時掃描磁場與表面原子形貌的技術，我們稱之為SSTM。眾所周知，掃描超導量子干涉元件具有很高的探測磁場靈敏度，而掃描穿隧電子顯微鏡有極高的空間解析度與電子能態的解析能力，因此他在超導特性上的電性分析是一個強而有力的工具。所以，我們新發展出來的 SSTM在電性與磁性上同時有很好的空間解析能力與微小訊號的的攝取能力，能分析樣品表面磁場和電性的相關性。我們除了介紹儀器的架設過程，也用之於鈮超導體與超巨磁阻鑭鈣錳氧化合物上的研究，各取得了一些有趣的結果。發現鈮超導體在外加磁場下，其超導能隙隨著靠近侷限磁場處會產生變化；也發現鑭鈣錳氧化合物在均勻的外加磁場下，會有磁波紋的產生。雖然產生這現象的原因還未十分明瞭，但是已可看出SSMT是一個研究新物理與新材料的有力工具。

This thesis contains two research subjects. In the first part, we constructed a scanning tunneling microscope (STM) and used this STM system to study the superconductivity of FeSe0.3Te0.7 thin films. The FeSe0.3Te0.7 sample, fabricated using pulse laser deposition, was designed to have two orientations of grains on the same MgO substrate with an angle between these two grains at about 45 degree. Significant enhancement of superconducting energy gap from 1.78 meV to 18.6 meV near the grain boundary region was observed. Since the grains of these two orientations squeeze each other in the boundary region to generate substantial strain force, we suggest that the superconductivity of FeSeTe can be enhanced in the strained region.
In the second part, we developed an instrument that can probe the distribution of magnetic fields and surface topography simultaneously by integrating scanning SQUID and STM into one, which is named as Scanning Squid Tunneling Microscope (SSTM). It is well known that scanning SQUID has a high sensitivity in detecting magnetic flux, and STM can resolve surface topography and probe electric properties at atomic scale. This newly designed SSTM system is therefore a powerful tool to analyze the correlations between magnetic and electric properties of intended sample surfaces. We demonstrated the capabilities of this SSTM system by measuring the superconducting Nb films and the colossal magnetoresistive La0.67Ca0.33MnO3 films. We have found an interesting evolution of superconducting energy gap of Nb varying symmetrically in a trapped magnetic flux region, and some periodic magnetic field ripples of the La0.67Ca0.33MnO3 films in the presence of a uniform external magnetic field. Although the physical origins of these observations are still unclear, our SSTM is undoubtedly proven a powerful instrument to explore new physics and new materials.

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