兰州大学机构库 >物理科学与技术学院
稀磁氧化物的制备及其铁磁性研究
Alternative TitleSynthesis and Ferromagnetism Properties of Diluted Magnetic Oxides
杨贵进
Thesis Advisor薛德胜
2012-05-26
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name博士
Keyword稀磁氧化物 室温铁磁性 氧缺陷 纳米颗粒
Abstract稀磁氧化物材料因其具有优异的性能在新型光电磁信息材料、微电子器件特别是自旋电子学器件、化学和生物等领域具有广阔的应用前景,是当前国际上新材料发展的一个重要方向和研究的前沿热点。本博士论文从研究其室温铁磁性的起源出发,探索了稀磁氧化物的室温铁磁性的调控和起源,得到了规律性的结果,并对其机理进行了分析,得到主要结果如下: 1、通过真空热处理,诱导出CoO单晶纳米微球的室温铁磁性,表明CoO纳米微球的室温铁磁性来源于样品表面的氧缺陷,通过控制纳米微球的尺寸,从而可以实现铁磁性的调控。 2、采用水热法加后期热处理的工艺制备了形貌可控的多孔Co3<下标!>O4<下标!>层状纳米阵列,并还将该方法推广,制备出了层状的NiO结构。 3、研究了在不同气氛条件下退火对CoO/Co3<下标!>O4<下标!>核壳结构的铁磁性的影响。结果表明,CoO/Co3<下标!>O4<下标!>核壳结构的室温铁磁性来源于氧缺陷,同时在这种核壳结构中还观察到了交换偏置现象。 4、研究了Al2<下标!>O3<下标!>纳米颗粒的不同晶体结构对其室温铁磁性的影响。结果发现:非晶的Al2<下标!>O3<下标!>纳米颗粒的铁磁性最强,随着结晶性逐渐变好,铁磁逐渐减弱。通过控制煅烧温度和后期真空热处理来实现对铁磁性强弱的调控。
Other AbstractDilute magnetic oxides have been in the forefront of applied research for various fields. In this PhD thesis, we mainly study the topics on origion of room temperature ferromagnetism and modulating the ferromagnetism. The major finding and innovations are shown as follow: 1.Single-crystalline CoO nanospheres were prepared by a solvothermal method. Magnetic measurements indicate that the vacuum-annealed samples show room temperature ferromagnetism after being post-annealed in vacuum atmosphere. 2.Porous hierarchical nanostructures of Co3<下标!>O4<下标!> were controllably and exclusively synthesized by hydrothermal method combined with subsequent calcination. 3.The prepared the CoO/Co3<下标!>O4<下标!> core-shell structure, in air or gas mixture of Ar and O2<下标!>, respectively. The results showed that the core-shell structure was prepared in Ar and O2<下标!> gas mixture shows room temperature ferromagnetism. 4.Amorphous and crystalline Al2<下标!>O3<下标!> nanoparticles were synthesized by sol-gel method with post-annealing at different temperatures. Magnetism measurements have indicated that all Al2<下标!>O3<下标!> nanoparticles exhibit intrinsic room temperature ferromagnetism.
URL查看原文
Language中文
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/229203
Collection物理科学与技术学院
Recommended Citation
GB/T 7714
杨贵进. 稀磁氧化物的制备及其铁磁性研究[D]. 兰州. 兰州大学,2012.
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