期刊
AIP ADVANCES
卷 7, 期 6, 页码 -出版社
AIP Publishing
DOI: 10.1063/1.4986905
关键词
-
资金
- JSPS KAKENHI Grant [JP26286021, JP16K13640]
- Hatakeyama Culture Foundation
- Foundation for Interaction in Science & Technology, Japan
- Izumi Science and Technology Foundation
- Grants-in-Aid for Scientific Research [15H04141] Funding Source: KAKEN
We have studied formation and stability of core-shell structures in epitaxial Au/Co nanoparticles (NPs) by using atomic-resolution scanning transmission electron microscopy. As the particle size reduces, number of NPs having Au-shell increases and their frequency of occurrence reached 65%. Au segregation proceeds during particle growth at 520 K. The core-shell structure formation is particle size-dependent; the critical diameter dividing the Au-shell and the Co-shell structures is about 11 nm, below which the Au-shell is stable. After annealing at 800 K for 3.6 ks, Au-shell NPs were conserved while the Co-shell NPs changed to two-phase structures with a planar interface separating Au and Co. There is a local energy minimum where the Co-shell NP is metastable in the as-deposited state. A simple model based on surface and interfacial energies suggests stability of Au-shell structures. Surface-segregation-induced phase separation in small NPs, due to low surface free energy of Au, will be responsible for the Au-shell formation. (C) 2017 Author(s).
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据