稀土-过渡金属间化合物纳米胶囊的制备及其室温磁制冷机理研究

项目名称： 稀土-过渡金属间化合物纳米胶囊的制备及其室温磁制冷机理研究

项目编号： No.51271178

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 马嵩

作者单位： 中国科学院金属研究所

项目金额： 80万元

中文摘要： 采用等离子体电弧共蒸发技术，制备居里温度高于室温的石墨包裹稀土-过渡金属间化合物RxMy纳米胶囊。系统研究不同制备条件对胶囊的物相与尺寸可控性的影响规律。深入研究胶囊的物相组成、元素掺杂等对其本征磁性质的调制规律。探索利用结构因素与尺寸大小调节胶囊的居里温度和冻结温度向室温移动的物理机制。利用胶囊磁相变与超顺磁现象同时出现在室温附近，得到室温附近具有宽制冷温区与最高磁熵变的最佳体系。建立磁性、结构、外场（温度与磁场）与胶囊室温磁熵变之间关系的半经验数学模型。在胶囊表面链接表面活性剂，减少胶囊间的团聚与相互作用。将胶囊制备成磁流体，在室温制冷样机上测试胶囊的磁制冷效率。本项目研究为开发新型室温磁制冷纳米材料提供了新的思路，为深入理解稀土-过渡金属间化合纳米胶囊在室温下具有高磁熵变的物理机制提供实验和理论指导。

中文关键词： 金属间化合物；纳米胶囊；磁熵变；磁矩密度；磁晶各向异性

英文摘要： The RxMy nanocapsules with graphite layers as shells and magnetic intermetallic compounds as cores will be prepared by the plasma arc-discharge technique. The compound cores are composed of lanthanide and transition metal elements and the magnetic cores have the characteristic that their Curie temperatures are higher than room temperature. We will systematically research the growth regularity of the nanocapsules with controlled phase composition and size distribution. The correlation between the magnetic properties and phase composition, doped elements of the nanocapsules will be studied in detailed. The principle that the Curie temperature and blocking temperature of the nanocapsules shift to room temperature through tuning the structure and size of the nanocapsules will be studied. In further, the nanocapsule system with wide refrigeration temperature range and highest magnetic entropy change at room temperature would be exploited, because we can utilized the characteristic that their magnetic phase transformation and superparamagnetic properties appear at room temperature at the same time. We also try to construct the semi-theoretical model to describe the correlation between the magnetic entropy change of the nanocapsules and their magnetic properties, structure, magnetic field and temperature. The active ag

英文关键词： intermetallic compound；nancapsule；magnetic entropy change；magnetic moment density；anisotropy