Coalescence and sintering of Pt nanoparticles: in situ observation by aberration-corrected HAADF STEM

被引：136

作者：

Asoro, M. A. ^{[1
]}

Kovar, D. ^{[1
,2
]}

Shao-Horn, Y. ^{[3
,4
]}

Allard, L. F. ^{[5
]}

Ferreira, P. J. ^{[1
,2
]}

机构：

[1] Univ Texas Austin, Mat Sci & Engn Program, Austin, TX 78712 USA

[2] Univ Texas Austin, Dept Mech Engn, Austin, TX 78712 USA

[3] MIT, Dept Mech Engn, Cambridge, MA 02139 USA

[4] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA

[5] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 USA

来源：

NANOTECHNOLOGY | 2010年 / 21卷 / 02期

基金：

美国国家科学基金会;

关键词：

SURFACE-DIFFUSION; PLATINUM; TEMPERATURE; INSTABILITY;

D O I：

10.1088/0957-4484/21/2/025701

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

An aberration-corrected JEOL 2200FS scanning-transmission electron microscope (STEM), equipped with a high-angle annular dark-field detector (HAADF), is used to monitor the coalescence and sintering of Pt nanoparticles with an average diameter of 2.8 nm. This in situ STEM capability is combined with an analysis methodology that together allows direct measurements of mass transport phenomena that are important in understanding how particle size influences coalescence and sintering at the nanoscale. To demonstrate the feasibility of this methodology, the surface diffusivity is determined from measurements obtained from STEM images acquired during the initial stages of sintering. The measured surface diffusivities are in reasonable agreement with measurements made on the surface of nanoparticles, using other techniques. In addition, the grain boundary mobility is determined from measurements made during the latter stages of sintering.

引用

页数：6

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