Layer resolved structural relaxation at the surface of magnetic FePt icosahedral nanoparticles

被引：149

作者：

Wang, R. M. ^{[1
,2
]}

Dmitrieva, O. ^{[3
,4
]}

Farle, M. ^{[3
,4
]}

Dumpich, G. ^{[3
,4
]}

Ye, H. Q. ^{[5
]}

Poppa, H. ^{[2
]}

Kilaas, R. ^{[2
]}

Kisielowski, C. ^{[2
]}

机构：

[1] Beijing Univ Aeronaut & Astronaut, Sch Sci, Beijing 100083, Peoples R China

[2] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA

[3] Univ Duisburg Essen, Fachbereich Phys, D-47048 Duisburg, Germany

[4] Univ Duisburg Essen, Ctr Nanointegrat, D-47048 Duisburg, Germany

[5] Peking Univ, Dept Phys, Beijing 100871, Peoples R China

来源：

PHYSICAL REVIEW LETTERS | 2008年 / 100卷 / 01期

关键词：

D O I：

10.1103/PhysRevLett.100.017205

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The periodic shell structure and surface reconstruction of metallic FePt nanoparticles with icosahedral structure has been quantitatively studied by high-resolution transmission electron microscopy with focal series reconstruction with sub-angstrom resolution. The icosahedral FePt nanoparticles fabricated by the gas phase condensation technique in vacuum have been found to be surprisingly oxidation resistant and stable under electron beam irradiation. We find the lattice spacing of (111) planes in the surface region to be size dependent and to expand by as much as 9% with respect to the bulk value of Fe(52)Pt(48). Controlled removal of the (111) surface layers in situ results in a similar outward relaxation of the new surface layer. This unusually large layerwise outward relaxation is discussed in terms of preferential Pt segregation to the surface forming a Pt enriched shell around a Fe-rich Fe/Pt core.

引用

页数：4

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