BiFeO3(BFO)為目前在鐵電與磁性元件應用上最有潛力的材料之ㄧ，這是因為BFO比起其它的複鐵式材料具有很高的居禮溫度TC(~850oC) 和尼爾溫度TN(~370oC)，在室溫下同時具有鐵電與鐵磁特性，相較於大部份的複鐵式材料，其尼爾溫度TN均在室溫以下，無法達到室溫應用的要求，也使得在實際的應用上有其限制。

本研究主要是探討BFO以不同比例之錳摻雜量[BiFe1-xMnxO3，其中x=0,0.1,0.2,0.3,0.4，簡稱為BFMO]對BFO之性質影響與改變，由於BiMnO3(BMO)是一種鐵磁性材料，其磁轉換溫度為105K，遠低於BFO之磁轉換溫度640K，而且Mn3+離子與Fe3+離子之半徑相近，因此本實驗希望在BFO之鈣鈦礦結構中，藉由Mn3+離子置換Fe3+離子來改善BFO之磁性質。

本實驗利用磁控濺鍍法使薄膜沉積在基板上，經過退火處理之 後，再進行一連串之性質分析，利用X光繞射儀(XRD)分析薄膜之結晶性， 利用化學分析電子光譜儀(XPS)探討離子之鍵結情況，利用場放射型掃描式電子顯微鏡(FE-SEM)觀察薄膜表面之微結構，利用原子力顯微鏡(AFM)觀察表面形貌，最後，再利用超導量子干涉震動磁量儀(SQUID VSM)測量薄膜之磁滯曲線，以了解薄膜之磁性表現。

我們可由實驗結果發現，從XRD分析可知隨著Mn之添加量愈多，則有愈多之雜相生成，顯示Mn並無法無限固溶於BFO中，而經由XPS之分析可知Mn離子主要是以正三價取代Fe離子正三價居多，由SEM分析可知Mn之掺雑量愈多，則晶粒有逐漸縮小的趨勢，而經由AFM之觀察可知隨著Mn之添加量愈多，則BFO之表面愈粗糙，此外，透過SQUID測量可以發現，微量之Mn添加時(x=0.1)，會使飽和磁化強度(Ms)明顯提升。

BiFeO3(BFO) is one of the most potential multiferroic materials for new device applications. This is because BFO has high ferroelectric Curie temperature (850oC) and antiferromagnetic Neil temperature (370oC), which are both above room temperature. This research mainly investigated the effects of manganese doping, i.e. BiFe1-XMnXO3 x = 0, 0.1, 0.2, 0.3, 0.4, on the BFO properties. Because BiMnO3 (BMO) is a ferroelectric ferromagnet and also, Mn3 + ion has a similar radius to Fe3 + ion, it was expected to be able to replace some Fe3 + with Mn3 +, resulting in new magnetic properties in the mixed compound BiFe1-XMnXO3 (BFMO).

This experiment utilized RF magnetic sputtering to deposit films on the Si, SrTiO3 and LaAlO3 substrates at room temperature, which were subsequently sintered at high temperatures to form the desired phase. X-rays diffraction (XRD) was used to analyze the phase purity and structures of the prepared films, X-ray photoelectron spectroscopy (XPS) was used to study the ion bonding valence, field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) was used to observe the surface morphology of the films, and finally superconducting quantum interference device (SQUID) was used to measure the magnetization-magnetic field (M-H) hysteresis loops in order to understand the magnetic properties of the films.

We found that more impurity phases appeared with more addition of Mn, indicating that there was a limit for Mn doping in BFO. By the XPS analysis, it was shown that with the increased amount of Mn doping, the grain size of films became smaller . AFM showed that the more Mn addition, the rougher of the surface. It was also found by SQUID measurement that with the addition of Mn (x=0.1) , there was an increase of the saturated magnetization of the doped films.

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