Photochromic Magnetic Materials

Incorporation of organic photochromes into magnetic systems not only provides new ways to photo‐control magnetic behavior but may also lead to interesting photochromic behavior. Cationic spiropyrans exhibit this type of behavior depending on whether the structure is open or closed (see Figure). These structures can also be incorporated into rigid layered MnPS₃ materials where reversible photo‐switching of magnetic coercivity is observed.     

Morphosynthesis of Molecular Magnetic Materials

Although molecule‐based materials can combine physical and chemical properties associated with molecular‐scale building blocks, their successful integration into real applications depends also on higher‐order properties, such as crystal size, shape, and organization. New approaches involving templating and self‐ or facilitated assembly of nanoscale building blocks to prepare novel multifunctional molecular magnetic materials with complex form and organization are described.     

研究发展中的磁致冷材料

本文分析比较了各种磁致冷材料的居里点Ｔｃ和磁热效应（等温磁熵变｜△ＳＭ｜或绝热去磁温度变化△Ｔａｄ）。较说细地总结了国内外不同温区的磁致冷材料的研究成果,并介绍了国内外磁致冷材料的最新研究进展－－如果具有巨磁热效应的钙钛矿型化合物以及９７年获得突破性进展、可望近年来投入商业使用的ＧｄＳｉＧｅ系合金。     

Lamellar Self-Assembly Nanostructured Magnetic Materials

Synthesis of lamellar self-assemblies symmetric polystyrene–polybutylmethacrylate (PS–PBMA) copolymers, doped by magnetic nanoparticles was described. Self-assembly is a spontaneous process by which molecules and nanophase entities may materialize into organized aggregates or networks. As soon as particles are coated by a grafted PS layer, they can be confined in the PS layer of the polymeric smectic. The lamellar order was maintained up to volume fractions of particles of 25% as determined by transmission electron microscopy. This volume fraction may be increased by addition of the PS homopolymer to the structure or by increasing the molecular weight of the diblock copolymer.     

热疗用磁性材料研究进展

在介绍热疗用磁性材料研究概况的基础上,对其研究进展进行了详细综述,重点介绍了Fe3O4和γ-Fe2O3两类材料的制备方法、产热能力研究以及动物实验等方面的内容,最后对热疗用磁性材料的发展前景进行了展望.     

稀土超磁致伸缩材料的磁场热处理研究

超磁致伸缩材料是一种先进的能量转换材料,在高新技术和国防军工领域具有重要的应用价值。在概述TbDyFe超磁致伸缩材料的特点及发展现状基础上,重点介绍了<110>取向材料的磁场热处理研究。在实验方面,采用区熔定向凝固技术制备了<110>取向TbDyFe多晶材料,在略高于居里点温度退火时施加磁场,不改变晶体学择优取向和凝固组织,但能调控初始磁畴分布状态,改变服役时的磁矩运动过程,从而改善材料磁致伸缩和力学性能。在模拟研究方面,建立了基于能量最低原理的磁畴旋转模型,模拟了磁热感生各向异性诱导的初始磁矩再取向过程,得到了形成单轴各向异性的临界值;模拟了感生各向异性强弱对磁致伸缩"Jump"效应的影响规律,探讨了磁场热处理对<110>取向晶体磁致伸缩的作用机理。     

纳米磁性材料及其应用

纳米磁性材料是纳米材料中最早进入工业化生产,应用十分广泛的一类功能材料,纳米磁性材料的特性不同于常规的磁性材料,其原因在于与磁性相关联的特征物理长庆恰好处于纳米量级,例如,磁单畴尺寸,超顺磁性临界尺寸,交换作用长度,以主电子平均自由路磁程自由路程等大致处于1－100nm量级,当磁性体的尺寸与这些特征物理长度相当时,就会呈现反常的磁学与电学性质,利用这些新特性,已涌现出一系列新材料与众多应用。     

磁性材料中的晶粒相互作用

磁性材料中的晶粒相互作用对材料的宏观磁性有决定性影响。相互作用可分为晶粒之间的长程静磁相互作用和近邻晶粒之间的交耦合相互作用。     

磁制冷材料的研究进展

本文简述了磁制冷的基本原理,分析磁制冷工质的熵特性,总结了近几年磁制冷材料的最新进展,对磁制冷材料未来的发展进行了展望。     

Hopkinson Effect in Soft Magnetic Materials

1. IntroductionIt is well known that the initial permeability ofmany ferromagnetic materials increases with increasing temperature and appears a sharp peak just before the Curie point, and then drops off to a verysmall value. The peak is called the Hopkinson peakand the phenomenon is normally called the Hopkinson effectll]. Since this effect is valid for all the ferromagnetic materials, it has been used as a methodto measure the Curie temperature. However, in ourresearch work of nanocrystall…     

磁性材料的新应用

介绍了磁性材料的性能、新效应和新应用 ,并指出了今后研究和开发的重点。     

纳米晶软磁材料的发展、磁特性及展望

本文首先回顾了纳米晶软磁材料的发展过程。对其合金化、磁性能特别是制备工艺作了较详细的介绍，分析了优异软磁性能的起因，最后对纳米晶软磁材料的发展趋势作了展望。