本計畫主要的目的在探討高溫超導體的磁通釘扎機制,假設樣品是由週期性陣列之釘扎中心所組成,而釘扎中心能量為指數型態,我們計算磁通蠕動所產生的電阻,變換不同的釘扎中心的大小或距離,我們也找到最佳化的釘扎中心大小,另外我們也仔細測量樣品隨磁場變化的電阻,其電壓被量測到很低的電壓,我們發現到用超導磁通蠕動模型可以有效的解釋此一實驗數據結果,也說明了磁場對溫度的相圖。 The purpose of this study will investigate the mechanism of flux pinning for high-Tc superconductors. We assume a periodic array pinning centers in the superconducting thin films, which the potential energy of the pinning centers has a exponential form, and simulate to calculate the resistivity of flux creep. When we make a variation in the distance between pinning centers and the pinning size, we find the optimal pinning size which has minimal dissipative energy. Further, the resistivity of the samples with magnetic fields are measured under very low voltage in detail. Using the flux creep model, we can explain the data reasonably, and illustrate the magnetic field-temperature phase diagram.