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Co掺杂稀磁性ZnO薄膜的制备

时间:2019-08-23 18:53来源:毕业论文
采用超声喷雾热解法(USP)制备Co掺杂ZnO稀磁薄膜样品,并采用X射线衍射(XRD)、X射线光电子能谱(XPS)和超导量子干涉(SQUID)等测试手段研究其结构和磁性能,进而讨论其磁性来源

摘要稀磁半导体(DMSs)材料同时利用了电子的电荷和自旋属性,具有优异的磁、磁光、磁电等性能,因此在材料科学和自旋电子器件领域具有广阔的应用前景。近年来,采用磁性离子注入技术,发现了ZnO半导体在室温下具有铁磁有序性。基于ZnO稀磁半导体在自旋电子器件方面的潜在应用价值,推动了国内外材料研究工作者的广泛研究,其中Co掺杂ZnO基稀磁半导体的研究尤其引起了许多人的关注,但实验对其铁磁性的来源还存在诸多争议。本课题采用超声喷雾热解法(USP)制备Co掺杂ZnO稀磁薄膜样品,并采用X射线衍射(XRD)、X射线光电子能谱(XPS)和超导量子干涉(SQUID)等测试手段研究其结构和磁性能,进而讨论其磁性来源。实验发现,单独Co的样品中铁磁性是是因为材料中出现了某种顺磁相,而N-Co共掺的样品的铁磁性是来源于空穴为媒介的束缚磁极化子。39024
毕业论文关键字:Co掺杂,超声喷雾热解法,ZnO薄膜,稀磁半导体,铁磁性
Abstract  Diluted magnetic semiconductors (DMSs) materials make use of charge and spin properties of electrons at the same time, and it has a broad application prospect in the field of spin electronic devices and materials science, due to its excellent magnetic,magneto-optical, and magnetic-electric properties. In recent years, by using the magnetic ion injection technology, it has been found that ZnO semiconductor has a ferromagnetic ordering at room temperature. In the whole world, many material researchers have made great efforts to research transition-mental doped ZnO due to their potential application in spintronics, and the study of Co-doped ZnO-based DMSs has especially aroused many people’s attention, however there exists still a lot of disputes on the origin of room temperature ferromagnetism in ZnO system. In this paper, we have prepared the Co-doped ZnO diluted magnetic thin films by a simple chemical vapor deposition method, i.e., ultrasonic spray pyrolysis (USP) technique. The structure and magnetic properties were explored by the X-ray diffraction (XRD), X-ray photoelectron pectroscopy (XPS) and superconducting quantum interference (SQUID), and then the origin of magnetism was discussed. By experimental analysis, it is considered that the ferromagnetism in Co-doped ZnO films results from the paramagnetic phase, while the magnetic property in N-Co doped ZnO films originates from the hole-mediated bound magnetic polarons. 源¥自%六:维;论-文'网=www.lwfree.cn
Key words: Co doping, ultrasonic spray pyrolysis (USP), ZnO thin films, diluted magnetic semiconductors (DMSs), ferromagnetism
目录
1.绪论
1.1 引言    4
1.2 研究背景和意义    4
1.3 ZnO晶体结构和物理特征    5
1.3.1 ZnO 的晶体结构    5
1.3.2 ZnO的电学特性    6
1.3.3 ZnO的光学特性    6
1.4 ZnO稀磁掺杂体系的研究进展    7
1.4.1 Co掺杂体系    7
1.4.2 Mn掺杂体系    8
1.5 ZnO薄膜的制备方法    8
1.5.1 分子束外延(MBE)    8
1.5.2 脉冲激光沉淀法(PLD)    8
1.5.3 化学气相沉淀法(MOCVD)    9
1.5.4 溅射法    10
1.5.5溶胶-凝胶法(gol-gel)    10
1.5.6喷雾热解法(SP)    11
1.6 选题依据    11
1.6.1选题依据    11
1.6.2 主要研究内容    11
2.1 材料制备方法    12
2.2 性能表征手段    13
2.2.1 X射线衍射分析(XRD)    14
2.2.2 XPS    14
2.2.3 光致发光光谱PL    14
2.2.4 超导量子干涉仪(SQUID)    14 Co掺杂稀磁性ZnO薄膜的制备:http://www.lwfree.cn/cailiao/20190823/38120.html
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