利用飛秒光譜檢測具應變釔錳氧薄膜內錳離子d-d能隙與尼爾溫度之研究

Abstract

此論文中，我們利用脈衝雷射鍍膜系統分別於MgO(100), MgO(111)與YSZ(111)三種基板上成功地製備沿c軸(001)成長的釔錳氧化物薄膜。並以X光繞射儀、四環繞射儀等量測晶格不匹配所對應樣品的晶格結構以及其應變效應。進一步，我們藉由可變波長之飛秒雷射激發-探測系統(OPOP)研究這些磊晶應變效應對釔錳氧化物錳離子之間d軌域躍遷能隙(Edd)以及尼爾溫度(TN)的影響。

In this thesis, we prepared pure (001)-oriented h-YMnO3 thin films on (100)MgO, (111)MgO and (111)YSZ substrates by pulsed laser deposition(PLD), respectively. And we get the crystal structure and strain effect of these thin films by X-ray diffraction and phi-scan. In further, we will show the results of the ultrafast dynamics in these samples probed by the tunable wavelength optical pump-optical probe technique. Especially, the influence of epitaxial strain due to lattice mismatch between the substrate and h-YMO films on the magnitude of Edd and Néel temperature (TN).