稀土铁石榴石磁光材料及其应用

本文综述了稀土铁石榴石磁光材料及磁光器件研究的最新进展；对最具应用价值的高掺Ｂｉ系列和掺Ｃｅ系列石榴石磁光材料作了介绍，在磁光器件方面选择了最具代表性的磁光隔离器和光纤电渗／磁场测试仪加以讨论。     

光纤传感器用磁光玻璃的研究进展

简述了磁光玻璃中Faraday效应的本质特征；综述了磁光玻璃的研究进展；对在光纤传感器中有潜在应用前景的高掺稀土玻璃材料作了介绍，并对当前磁光玻璃研究中存在的问题进行了讨论。     

新一代磁光材料及器件研究进展

磁光材料是典型的多功能材料,其应用频率覆盖了射频、微波、毫米波、THz波和光波段,是一类优秀的全波段材料.首先对磁光材料发展的动态进行了分析;其次就磁光材料应用于磁光盘、光纤通信器件、THz器件等进行了讨论;最后,对作者课题组的一些新的研究工作做了介绍,以期能对这一领域的发展起到促进作用.     

离子掺杂钇铁石榴石磁光材料研究进展

综述了钇铁石榴石型磁光材料的研究进展,以及通过离子掺杂提高单晶和薄膜材料的比法拉第旋转角、改善材料温度稳定性以及近年来受到重视并有望在磁光器件中得到广泛应用的低成本钇铁石榴石纳米晶/有机分散介质复合薄膜材料的研究进展与存在的问题,概述了目前实际使用中的磁光法拉第转子材料的应用情况,并展望了高性能磁光材料的发展。     

光隔离器及其相关的磁光材料

本文简要介绍了磁光隔离器的理论、结构和分类，并提出了该器件今后发展的几个问题，是最后介绍了几种磁光材料。     

光隔离器及其相关的磁光材料

本文简要介绍了磁光隔离器的理论、结构和分类 ,并提出了该器件今后发展的几个问题 ,最后介绍了几种磁光材料     

新型掺钆铁石榴石磁光薄膜材料

对新型掺钇石榴石磁光薄膜材料的制备工艺、磁光特性及理论分析进行了较全面的评述，并指出今后研究的方向。     

新型掺铈钇铁石榴石磁光薄膜材料

对新型掺铈钇铁石榴石磁光薄膜材料(Ce:YIG)的制备工艺、磁光特性及理论分析进行了较全面的评述,并指出今后研究的方向。     

石榴石型磁光存储材料

稀土铁石榴石薄膜被认为是最具应用前景的下一代磁光记录材料。稀土铁石榴石薄膜具有高的矫顽力、良好的热、化学稳定性及强的磁光效应等特点；特别是当Ｂｉ３＋和Ｃｅ３＋离子部分取代石榴石结构中的稀土离子后，可以极大地增强其磁光效应。本文就磁光记录的原理、磁光存储材料、稀土铁石榴石磁光薄膜的制备及其如何降低石榴石薄膜中的晶界噪声等问题作了一些探讨。     

用于高性能光隔离器的复合稀土铁石榴石ReYbBiIG单晶材料研究

通过加速旋转坩埚技术和Bi₂O₃/B₂O₃助溶剂生长技术研制新型磁光复合稀土铁石榴石单晶ReYbBiIG(Re:Tb³⁺、Ho³⁺、Y³⁺。从理论上解释了将两种具有相反符号法拉第温度和波长系数的掺铋稀土铁石榴石复合可以显著优化磁光性能,并成功制得具有大磁光优值、低饱和磁化强度、低近红外吸收、极小法拉第温度和波长系数的系列优质磁光单晶(如:Ho_0.85Yb_1.12Bi_1.03Fe₅O₁₂和Tb_2.06Yb_0.46Bi_0.48Fe₅O₁₂等)。研究表明,以新型磁光复合稀土铁石榴石单晶ReYbBiIG作为法拉第转子材料制得的新型光隔离器更适用于WDM光纤通讯系统对宽波段和温度稳定性的要求。     

Bi3+、Ce3+离子极大增强铁石榴石磁光法拉第效应微观机制研究

采用单离子晶格模型,以磁光量子理论计算了Bi 3+、Ce3+离子替代的稀土铁石榴石晶体中Bi3+、Ce3+离子的晶场能级,波函数及能态间电偶极跃迁几率,进而计算了Bi3+、Ce3+离子对法拉第旋转角θF的贡献,获得了与实验符合较好的计算结果,加深了对Bi3+、Ce 3+离子极大增强铁石榴石磁光效应微观机制的认识。,The split energy levels,occupation probabili ties,wave function and electrical dipole transition induced by crystal field and exchange interaction for the Ce3+ ions in Ce3+-substituted and the Bi3+ ions in Bi3+-substituted iron garnets at room temperature bas ed on quantum theory has been calculated.Furthermore,the calculation of the Fara day rotation contributed by the Ce3+ and Bi3+ ions has also been car ried out.The crystal field and the super-exchange interaction are two crucial f actors in determining the Faraday rotation.The theoretical results are in good t hose of experiments.     

The relationship between uniaxial anisotropy and composition in some magnetic bubble garnets

Data on the relationship between uniaxial anisotropy (Ku) and composition in a series of Ca, Ge substituted rare earth iron garnets for use in magnetic bubble memory devices are presented. These results largely support Eschenfelder's model, and a small modification to this model is proposed which improves the accuracy of the Ku prediction.     

Bi3.45Eu0.55Ti3O12铁电薄膜的光学性能

采用化学溶液沉积法在石英衬底上制备了Bi3.45Eu0.55Ti3O12(BEuT)铁电薄膜,研究了BEuT薄膜的结构和光学性能。XRD测试结果表明,BEuT薄膜皆形成铋层状钙钛矿型结构,其晶粒尺寸随着退火温度的提高而增加。薄膜的光学透过率曲线显示,在大于500nm的波段BEuT的透过率比较高,而其禁带宽度大约为3.61eV。BEuT薄膜的发光强度随着退火温度的提高,先是增强后减弱,在700℃时达到最大。这与薄膜的结晶状况有关。     

Morphology controlled synthesis of spherical Bi2S3 flowers

The spherical Bi2S3 flowers have been fabricated by a facile environmentally friendly hydrothermal method. It was found that the flowers are composed of pure orthorhombic phase Bi2S3, the nanorods (nanowires) composed of the flowers grow radically from a center toward all directions to form a spherical structure, and the nanowires are single-crystalline and grow along the [001] direction. The reaction time, reaction temperature and thiourea play key roles for the formation of the flowers. The morphology of the Bi2S3 flowers (e.g., honeycombs, porous nanorods, nanorods, and nanowires) can be controlled simply by controlling the reaction time without varying experimental parameters or addition of other surfactant. The formation mechanism of Bi2S3 flowers is self-assembly and the intrinsic splitting character of the Bi2S3 structure. The spherical Bi2S3 flowers could be found potential applications in optical, catalysts and sensor devices.     

Bi2WO6 nano- and microstructures: shape control and associated visible-light-driven photocatalytic activities

The shape-controlled synthesis of nano- and microstructured materials has opened up new possibilities to improve their physical and chemical properties. In this work, new types of Bi(2)WO(6) with complex morphologies, namely, flowerlike, tyre- and helixlike, and platelike shapes, have been controllably synthesized by a facile hydrothermal process. The benefits of the present work also stem from the first report on the transformation of Bi(2)WO(6) from three-dimensional (3D) flowerlike superstructures to 2D platelike structures, and on the formation of tyre- and helixlike Bi(2)WO(6) superstructures. UV/Vis absorption spectra show that the optical properties of Bi(2)WO(6) samples are relevant to their size and shape. More importantly, the photocatalytic activities of Bi(2)WO(6) nano- and microstructures are strongly dependent on their shape, size, and structure for the degradation of Rhodamine B (RhB) under visible-light irradiation. The reasons for the differences in the photocatalytic activities of these Bi(2)WO(6) nano- and microstructures are further investigated.     

Bi12TiO20晶体的全息性能

Ｂｉ１２ＴｉＯ２０晶体是一种优良的全息记录材料。本论文对纯Ｂｉ１２ＴｉＯ２０和掺Ｃｅ∶Ｂｉ１２ＴｉＯ２０晶体的衍射效率、半波电压、旋光度等性能进行了测试，并讨论了掺入的Ｃｅ对晶体性能的影响，Ｃｅ＾４＋离子在晶体中取代Ｂｉ＾３＋离子形成新的区域中心。此外还探讨了Ｔｉ原子对晶体旋光度的影响，认为Ｂｉ１２ＴｉＯ２０晶体旋光度远小于Ｂｉ１２ＳｉＯ２０、Ｂｉ１２ＧｅＯ２０的根本原因在于Ｔｉ原子的性质和极化不     

Size-dependent thermo-optical properties of embedded Bi nanostructures

The thermally induced optical transmission changes upon melting and solidification of Bi?nanostructures embedded in amorphous Al(2)O(3) thin films have been studied as a function of?characteristic sizes in the range 7-35?nm. The results show a repeatable optical transmission-temperature hysteresis loop with sharp changes at the melting and solidification temperatures. Both temperatures decrease linearly when the mean size of the nanostructures decreases and they are respectively higher and lower than that of the bulk melting temperature of Bi. The optical transmission shows a significant contrast that increases up to 16% as the mean size of the nanostructures increases. The results show that in addition to the usual decrease of melting temperature as the size of the nanostructures decreases, the melting temperatures for all samples are higher than that of the bulk. This unexpected result is associated to the contraction of Bi upon melting and to matrix effects related to the balance of surface energies between the solid and liquid Bi and the matrix. The solidification process shows a weaker dependence on the nanostructure size, and thus it is consistent with a mainly volume controlled process. It is shown that by controlling the characteristic dimensions of the Bi nanostructures the temperature operability of the Bi nanostructures embedded in amorphous Al(2)O(3) as a thermally driven optical switch can be tuned over 73?K.