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HUSTIR > College of Engineering > Department of Electrical Engineering & Graduate Institute > Theses and Dissertations > Item 310993100/3849

Please use this identifier to cite or link to this item: http://ir.hust.edu.tw/dspace/handle/310993100/3849

Title:	Bi1-xPrxFe0.95Mn0.05O3多鐵性薄膜鐵電及磁電特性研究 Study the ferroelectric and magnetoelectric properties of the Bi1-xPrxFe0.95Mn0.05O3 multiferroic thin films
Authors:	陳彥淳
Contributors:	電機工程研究所
Keywords:	溶膠凝膠薄膜多鐵電鐵電磁性介電性漏電流
Date:	2012-06
Issue Date:	2013-11-19T06:21:19Z
Abstract:	本研究以溶膠凝膠法製備BiFeO3 (BFO)多鐵性薄膜，透過旋轉塗佈法將薄膜沉積在Pt/Ti/SiO2/Si(100)基板上，並且利用RTA快速升溫爐在氧氣氛圍下做退火處理。本研究中實驗分為四個部分探討。首先為純相BFO薄膜經不同退火溫度熱處理後的特性比較。第二部分為摻雜微量的Mn，探討BiFe0.95Mn0.05O3 (BFMO)的特性。第三部分在Bi1-xPrxFe0.95Mn0.05O3薄膜中摻雜不同含量的Pr，探討Pr對薄膜的結構、磁及電特性的影響。最後為雙層多鐵性及鐵電薄膜製備，利用具高介電常數的Bi3.96Gd0.04Ti2.95W0.05O12 (BGTWO)薄膜作為雙層結構的底層，上層則成長Bi0.8Pr0.2Fe0.95Mn0.05O3 (BPFMO) 多鐵性薄膜，探討雙層結構薄膜的結構變化與磁電特性。由實驗結果得知純相BFO薄膜在退火溫度450 oC時有最佳的晶相，並且無二次相的產生。BFO薄膜摻雜Mn能有效抑制Fe3+與Fe2+間的變動，減少氧空缺產生，晶格結構因Mn的摻雜受到改變，而產生較佳的磁特性。Bi1-xPrxFe0.95Mn0.05O3薄膜摻雜不同含量的Pr分別為x=0.05、0.1、0.15、0.2。發現Pr摻雜量在x=0.15時晶格結構從菱形晶轉為正方晶，並且隨著Pr含量的增加到x=0.2時有最佳的鐵電特性其2Pr=29.18 μC/cm2和2Ec=119.2 kV/cm；當外加頻率在500 kHz時其介電常數為242.92；而外加電場在50 kV/cm時漏電流密度為3.44 x10-5 A/cm2；磁性量測飽和磁化率Ms為 0.14 emu/g。此外，在BPFMO/BGTWO雙層結構的薄膜中由於在退火處理時薄膜之間原子互相擴散的問題導致介面間更多的氧空缺產生，使雙層結構的薄膜比起單層BPFMO薄膜的鐵電特性略差一些。最後經實驗結果證實透過摻雜或異質結構的鐵電薄膜方式均能有效改善純相BFO薄膜的鐵電性、介電性、漏電流等問題。 The BiFeO3 (BFO) thin films were fabricated on Pt/Ti/SiO2/Si (100) substrates by using a sol-gel process and annealed by rapid thermal annealing in an oxygen atmosphere. In this study, the discussions of the experimental were divided into four parts. First, the properties of the pure BiFeO3 thin films annealed at different temperatures. Second, the behaviors of the BiFe0.95Mn0.05O3 (BFMO) thin films were studied. Third, the characteristics of different content of Pr doped in BFMO thin films were discussed. Finally, to discuss the properties of the Bi0.8Pr0.2Fe0.95Mn0.05O3 (BPFMO) multiferroic thin film/Bi3.96Gd0.04Ti2.95W0.05O12 (BGTWO) ferroelectric thin films. The pure BFO thin films have the best crystallization annealing at 450 oC, and without existing the second phase. Doping Mn in the BFO thin film can effectively restrain the transition between Fe3+ and Fe2+, also can reduce the oxygen vacancies. In addition, the Mn-substituted caused a crystal structure distorted, and produced the better magnetic properties. Pr-substituted in Bi1-xPrxFe0.95Mn0.05O3 (x=0.05, 0.1, 0.15 and 0.2) thin films produced a phase transition from rhombohedral to tetragonal structure at x=0.2. As the content of Pr increase to x=0.2 has the best ferroelectric properties with 2Pr=29.18 μC/cm2 and 2Ec=119.2 kV/cm, respectively. The Bi0.8Pr0.2Fe0.95Mn0.05O3 thin films have the dielectric of 242.92 at applied frequency of 500 kHz; the leakage current densities of 3.44 x10-5 A/cm2 at applied field of 50 kV/cm; and the saturation magnetization Ms=0.14 emu/g. In addition, the BPFMO/BGTWO thin films produced atoms diffusion between the interfaces, which caused oxygen vacancies. The double layer thin film has lower ferroelectric properties than the BPFMO thin film. From the experimental results demonstrate by doping with heterostructure prepared multiferroic thin films can effectively improve the properties of the ferroelectric, dielectric and leakage current.
Description:	指導教授:陳宏仁
Appears in Collections:	[Department of Electrical Engineering & Graduate Institute] Theses and Dissertations

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