以極化飛秒光譜研究(100)Y0.7Ca0.3Ba2Cu3O7-δ薄膜之超快動力學

Abstract

在本論文中，我們用PLD鍍膜系統成功的製作了(100)Y0.7Ca0.3BCO的薄膜，藉由X-ray、Φ-scan、AFM、SEM可以來確認薄膜軸向性的純度以及薄膜表面的平整性。並且利用控氧系統控制薄膜的載子濃度，透過四點量測可得知不同濃度與相變溫度Tc的關係，如：過度摻雜、最佳摻雜與不足摻雜的變化。之後透過我們發展成熟的極化飛秒光譜技術可以量測同一片樣品不同參雜在b軸以及c軸方向上，瞬時反射率隨著遲緩時間變化的情形。並且透過低溫系統可以量測樣品在不同溫度的反射率變化情形。

In this thesis, we have successfully prepared the (100)-oriented Y0.7Ca0.3BCO thin films by pulsed laser deposition (PLD). We confirmed purity of(100) Y0.7Ca0.3BCO thin film by measurement of X-ray andΦ-scan. Through SEM and AFM , We can check the roughness of thin film. Besides, We can understanding the relationship between different oxygen containment of the (100)Y0.7Ca0.3BCO film and Curie temperature by using the encapsulated bulk annealing method, i.e. overdoped, optimal doped and underdoped sample. The series of data are extracted from anisotropic ultrafast dynamics which is probed by polarized femtosecond spectroscopy. We obtained the complete data by changing the oxygen containment and temperature at only one sample.