纳米磁性材料及其应用

Nanostructured Magnetic Materials and Their Applications

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度恰好处于纳米量级,例如,磁单畴尺寸,超顺磁性临界尺寸,交换作用长度,以及电子平均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。

The nanostructured magnetic materials are a kind of functional materials which have wide applica- tions and were the first nanomaterials to be commercialised.The character of the nanostructured materials is different from traditional magnetic materials because the characteristic physical lengths which are associated with magnetism are at nano-metre scale.For example,the size of single magnetic domain,the critical size of superparamagnetism,the length of exchange interaction and the average free distance of electron etc.are all in the 1-100nm range.When the size of magnet nearly matches these characteristic physical lengths,unusual magnetic and electrical properties will be ob- served.Nanosturctured magnetic materials and their various applications are reviewed briefly in this paper.