Enhanced orbital magnetism in Fe50Pt50 nanoparticles
Enhanced orbital magnetism in Fe50Pt50 nanoparticles
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DOI：
10.1103/physrevlett.97.117201
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发表时间：
2006-09-15
影响因子：
8.6
通讯作者：
Sun, Shouheng
中科院分区：
文献类型：
--
作者：
Antoniak, C.;Lindner, J.;Sun, Shouheng
在通过软氢等离子体完全去除有机配体和覆盖颗粒的氧化物壳之前和之后，测量了平均直径为 6.3 nm 的湿化学合成单分散 Fe50Pt50 颗粒的 Fe 和 Pt L-3,L-2 边缘的 X 射线吸收和磁圆二色性光谱，从而形成纯金属态。金属颗粒经过热处理后，矫顽场增加了6倍，Fe位点的轨道磁矩增加了330%，Pt位点的轨道磁矩减少了30%，而有效自旋矩没有变化。 Pt L-3、L-2 边缘处扩展 X 射线吸收精细结构中振荡频率的降低为晶体学向 L1(0) 相变化提供了证据。
X-ray absorption and magnetic circular dichroism spectra at both the Fe and Pt L-3,L-2 edges were measured on wet-chemically synthesized monodisperse Fe50Pt50 particles with a mean diameter of 6.3 nm before and after complete removal of the organic ligands and the oxide shell covering the particles by soft hydrogen plasma resulting in a pure metallic state. After thermal treatment of the metallic particles, the coercive field increased by a factor of 6, the orbital magnetic moment at the Fe site increased by 330% and is reduced at the Pt site by 30%, while the effective spin moments did not change. A decrease of the frequency of oscillations in the extended x-ray absorption fine structure at the Pt L-3,L-2 edges provides evidence for crystallographic changes towards the L1(0) phase.