微結構與內長缺陷對釔鋇銅氧薄膜表面電阻之影響

Abstract

本論文研究高溫超導釔鋇銅氧薄膜的微結構與其內長缺陷對薄膜表面電阻之影響。利用改變鍍膜氧氣壓力條件，得到兩種不同表面型態的薄膜。經過薄膜與元件的微波量測，發現影響薄膜表面電阻的因素，並非完全決定於薄膜的表面平整度；另一方面，由傳輸特性及晶格常數與鍍膜氧壓的變化關係，我們推論薄膜結構中鋇取代釔的反應及內長缺陷應是影響表面電阻的重要原因。

In this thesis, we investigate the effects of microstructure and grown-in disorder on the surface resistance of YBCO thin films. We obtained two different YBCO thin films with distinct surface morphology by changing the oxygen partial pressure during pulsed laser deposition. The microwave measurement, however, revealed that the surface roughness of thin films is not decisive in determining the surface resistance. On the other hand, from the transport and crystalline structure analyses, it is suggestive that the Ba-Y antisite disorder and grown-in defects may dominate the surface resistance of YBCO thin films.