MAGNETISM FROM THE ATOM TO THE BULK IN IRON, COBALT, AND NICKEL CLUSTERS
MAGNETISM FROM THE ATOM TO THE BULK IN IRON, COBALT, AND NICKEL CLUSTERS
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DOI：
10.1126/science.265.5179.1682
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发表时间：
1994-09-16
期刊：
影响因子：
56.9
通讯作者：
DEHEER, WA
中科院分区：
文献类型：
--
作者：
BILLAS, IML;CHATELAIN, A;DEHEER, WA
对铁、钴和镍团簇的分子束偏转测量表明，在80-1000K温度范围内，随着团簇尺寸从几十个原子增加到几百个原子，磁性是如何发展的：即使是最小的尺寸也会发生铁磁性：对于小于30个原子的团簇，磁矩是原子状的；当尺寸增加到700个原子时，磁矩接近体积极限，振荡可能是由表面感应的自旋密度波引起的。用磁壳模型解释了这一趋势。在铁团簇中还发现了从高阶矩到低阶矩的结晶相变。
Molecular beam deflection measurements of small iron, cobalt, and nickel clusters show how magnetism develops as the cluster size is increased from several tens to several hundreds of atoms for temperatures between 80 and 1000 K. Ferromagnetism occurs even for the smallest sizes: for clusters with fewer than about 30 atoms the magnetic moments are atomlike; as the size is increased up to 700 atoms, the magnetic moments approach the bulk limit, with oscillations probably caused by surface-induced spin-density waves. The trends are explained in a magnetic shell model. A crystallographic phase transition from high moment to low moment in iron clusters has also been identified.