本實驗在分子束磊晶系統中於藍寶石基板製成鐵磁性拓樸絕緣體，其透過調控氣體分壓比、成長溫度方法，將磁性物質鉻(Chromium)摻雜入三元拓樸絕緣體(BixSb1-x)2Te3，形成四元拓樸絕緣體Cry(BixSb1-x)2-yTe3薄膜並對其研究。
首先是晶體結構部分，先由臨場(in situ)之反射式高能量電子繞射(Reflection high-energy electron diffraction,RHEED)初步判斷薄膜結構與平整度，再以X-光繞射儀量測觀測Cr摻雜使結構變化，其吸收光譜之趨勢也符合理論計算趨勢，並使用原子力顯微鏡AFM來觀察拓樸絕緣體層狀表面。元素分析部份，分別用拉曼光譜與X射線光電子能譜(X-ray Photoelectron Spectroscopy, XPS)，觀察樣品Cr元素成份的摻雜。
接著量測Cry(BixSb1-x)2-yTe3薄膜之磁性與電性。磁性部分，利用超導量子干涉(Superconducting Quantum Interference Device, SQUID)量測出在低溫下，Cry(BixSb1-x)2-yTe3薄膜有鐵磁性特性。電性傳輸則是將磁性拓樸絕緣體製成特定圖形，並量薄膜於低溫、弱磁場下是否有量子異常霍爾效應電性傳輸表現與特性。最後再製成磁性拓樸絕緣體/拓樸絕緣體/磁性拓樸絕緣體的三層異質結構，調控中間拓樸絕緣體厚度研究異質結構之電性表現，有無軸子態絕緣體的趨勢出現。

In this experiment, we grow the Cry(Sb1-xBix)2-yTe3 thin film on the sapphire substrate by the molecular beam epitaxy system. We change the rate of Cr vapor deposition to adjust the content ratio of Cr in film. The first experiment part is the crystal structure, we use in-situ reflective high-energy electron diffraction (RHEED)、X-ray Diffraction(XRD) to measure the roughness and single crystal of thin film. Then we check XAS is similar to the theoretical paper. And we use atomic force microscope (AFM) to show the morphology of the TI doped Cr. In element analysist part, we report Cr substitute Sb、Bi by the Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS).Since Cry(Sb1-xBix)2-yTe3 thin film is ferromagnetic at very low temperature, we investigate the magnetic property by Superconducting Quantum Interference Device (SQUID). We measure the ferromagnetic at 5K、20K、50K successfully. Then we lithograph sample to Hall bar pattern, and measure the electric transport property at 295K、16K、10K、5K. At PPMS temperature at 5K and 10K, we can find the quantum anomalous Hall effect under a weak magnetic field. Final we grow the MTI/TI/MTI and adjust the thickness of TI, we find that sample with 15nm TI has the behavior of axion insulator.

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