ZnO基稀磁半导体电磁特性的研究

发布时间：2018-02-24 04:46

本文关键词： ZnO Co掺杂 Mn掺杂电输运性质磁性　出处：《渤海大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文采用水热合成法分别制备了Co掺杂和Mn掺杂氧化锌纳米材料,对初始材料以及在空气中退火材料的电学和磁学性质进行了研究。通过X射线衍射(XRD)、扫描电镜(SEM)等仪器对制得样品的结构、形貌进行了表征,通过霍尔效应测试系统对样品的电输运性质和磁阻效应进行了分析,研究结果表明:(1)XRD结果显示Zn_(1-x)Co_xO样品为六方纤锌矿结构,钴元素以Co2+掺入氧化锌的晶格当中且不改变氧化锌的物相结构,但是XRD峰位均有不同程度的向右偏移(与掺杂浓度有关);SEM显示样品展现了不同形貌。通过XPS、Raman和FTIR分析表明Zn0.9Co0.1O合成材料为纯相结构,且没有其他物相存在;所有样品均表现为正磁阻效应。(2)Zn_(1-x)Mn_xO为六方纤锌矿结构,随着掺杂浓度的改变,XRD峰位有不同程度的向左偏移,晶格常数变大,退火后样品的晶粒尺寸变大;SEM测试显示材料合成形貌均为六棱柱,大小均匀。通过XPS、Raman和FTIR分析表明Zn_(1-x)Mn_xO合成材料有Mn的氧化物形成。未经热处理的样品均表现为负磁阻效应,这主要是由于电子局域化作用和能带劈裂效应共同作用的结果,退火后的样品内部晶格缺陷减少,水分子导电作用减弱,致使样品由负磁阻效应转变为正磁阻效应。霍尔效应和磁阻效应结果反应一致。
[Abstract]:In this paper, Co doped and mn doped ZnO nanomaterials were prepared by hydrothermal synthesis. The electrical and magnetic properties of the initial materials and the annealed materials in air were studied. The structure and morphology of the samples were characterized by means of X-ray diffraction (XRD), X-ray diffraction (XRD), scanning electron microscopy (SEM) and so on. The electrical transport properties and magnetoresistive effect of the samples were analyzed by Hall effect test system. The results show that the Zn_(1-x)Co_xO samples are hexagonal wurtzite structure. Cobalt is doped into the lattice of zinc oxide with Co2 and does not change the phase structure of zinc oxide. However, the peak positions of XRD were shifted to the right to different extent. The samples showed different morphologies. The results of FTIR and FTIR analysis showed that the Zn0.9Co0.1O synthesized materials were pure phase structure and no other phase existed. All the samples show positive magnetoresistive effect. The structure of the structure is hexagonal wurtzite. With the change of doping concentration, the peak position of X ray diffraction shifts to the left, and the lattice constant increases. After annealing, the grain size of the samples increased and SEM showed that the synthesized materials were all hexagonal and uniform in size. The results of Zn_(1-x)Mn_xO Raman and FTIR analysis showed that mn oxides were formed in the synthesized materials, and the samples without heat treatment showed negative magnetoresistive effect. This is mainly due to the interaction of electron localization and band splitting effect. The lattice defects in the annealed samples are reduced and the conductivity of water molecules is weakened. The results of Hall effect and magnetoresistive effect are consistent.
【学位授予单位】：渤海大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O472

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