兰州大学机构库 >物理科学与技术学院
铜基氧化物的室温铁磁性研究
Alternative TitleInvestigation of Room Temperature Ferromagnetism in Oxides of Copper
时守鹏
Thesis Advisor高大强
2016-05-29
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name硕士
Keyword铜基氧化物及其复合物 室温铁磁性 缺陷浓度 界面
Abstract氧化物稀磁半导体材料具有优异的光、电磁性能,在新型自旋电子学器件、光电磁信息材料、化学和生物领域都具有广泛的应用,是当前新材料发展的一个重要方向与研究热点。本论文针对当前稀磁氧化物半导体室温铁磁性的起源及如何调控其磁性的科学问题,以铜基氧化物为研究对象,探索了真空热处理、退火温度、复合物的比例以及缺陷浓度等对材料室温铁磁性的影响,得到了如下结果: 1、利用共沉淀法及后期热处理的方法制备了花状CuO纳米颗粒异质结构,研究了退火温度与退火时间对其形貌和铁磁性的影响。结果表明提高退火温度或者延长退火时间会改变样品的晶粒尺寸,同时也对样品的铁磁性进行了调控。真空热处理结果表明样品的铁磁性与颗粒表面或界面的氧空位直接相关。 2、通过热分解法制备了Cu2O/Cu和Cu2O/CuO复合纳米材料,研究了复合样品中两相比例对样品铁磁性的影响。结果表明,当两相的比例接近时,复合物中两相界面数增多,此时界面处Cu缺陷的数量最多。证明了这一体系中复合物的铁磁性来源与Cu缺陷相关,利用以氧缺陷为媒介的束缚磁极化子模型解释了复合纳米材料的铁磁性来源。因此通过调节复合样品中两相的比例去实现样品铁磁性的调控。 3、利用磁控溅射的方法制备了CuO薄膜,通过Ar离子辐照制造缺陷研究了缺陷浓度与铁磁性的关系。结果显示,随着辐照剂量的增加,由于样品结构发生相变,样品中Cu缺陷的浓度逐渐增加,同时样品的饱和磁化强度也增强。因此,我们可以通过控制辐照剂量来调节样品中Cu缺陷的浓度,从而达到对样品铁磁性的调节。
Other AbstractDilute magnetic oxides semiconductor have been in forefront and significant branch of applied researches for various fields, which include photo-electro-magnetic materials, spintronics devices, and chemical technology, and so on. Here,we focus on the ferromagnetic origin and adjustment of dilute magnetic oxides semiconductor through oxides of copper. We discussed the effect of vacuum annealing, annealing temperature, the ratio of composites and vacancy concentration to the room ferromagnetism of the samples. The main results are as follows: 1、 Flowerlike CuO nanostructures were prepared by co-precipitation and annealing method. The morphology and ferromagnetism of the samples were studied by changing annealing temperature and annealing time. The results indicate that we can change the crystal size of the samples by changing the annealing temperature and annealing time. Thus, the ferromagnetic of the samples can also be tuned. The results of vacuum annealing indicates that the ferromagnetism of the samples is related to oxygen vacancy at the surface or interface of nanoparticle. 2、 The Cu2O/Cu and Cu2O/CuO nanoparticle composites were fabricated by heating a mixture of copper nitrate with different amounts of glycine. Their magnetic properties were studied by adjusting the ratio to Cu2O and Cu or Cu2O and CuO. The results indicate that the amount of interface reach to the maximum when the ratio to two phases is close to equal. Due to the competition of two phase, amount of Cu vacancy appeared at the surface and the sample behave the highest saturation magnetization at this time, which indicates that the ferromagnetism is related to Cu vacancy. A bound magnetic polaron model is applied to explain the origins of ferromagnetism. Besides, the Ms of the composites can be tuned by adjusting the ratio of two phases. 3、 We deposited the CuO thin film using a magnetron sputtering system. Large amounts of artificial vacancies were made by argon ions irradiation CuO thin film. We find that the Cu vacancies concentration will increase when the irradiation dose increase. Meanwhile, due to the phase changing, the saturation magnetization of sample will be improved. Therefore, we can modulate the Cu vacancies concentration by control the irradiation dose, and further modulate the ferromagnetism of samples.
URL查看原文
Language中文
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/229253
Collection物理科学与技术学院
Recommended Citation
GB/T 7714
时守鹏. 铜基氧化物的室温铁磁性研究[D]. 兰州. 兰州大学,2016.
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