Temperature effect on the ordering and morphology of CoPt nanoparticles

被引：37

作者：

Penuelas, J. ^{[1
]}

Andreazza-Vignolle, C. ^{[1
]}

Andreazza, P. ^{[1
]}

Ouerghi, A. ^{[1
]}

Bouet, N. ^{[1
]}

机构：

[1] Univ Orleans, CNRS, Ctr Rech Mat Divisee, UMR 6619, F-45071 Orleans, France

来源：

SURFACE SCIENCE | 2008年 / 602卷 / 02期

关键词：

nanoparticles; CoPt alloy; magnetic materials; high resolution electron microscopy;

D O I：

10.1016/j.susc.2007.11.002

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

In the present work, we report a growth and structural study Of Co50Pt50 nanoparticles prepared on amorphous carbon substrate by ultra high-vacuum evaporation and investigated by transmission electron microscopy. The size evolution with the amount of CoPt shows a Volmer Weber behavior. At room temperature the nanoparticle diameter follows a t(0.41) power law. Temperature effect on the growth and chemical ordering is presented. A bimodal size distribution is observed and an evolution of particle composition is demonstrated for the nanoparticles prepared on heated substrate. The nanoparticles prepared at room temperature and annealed present an homogeneous size and composition evolution. Annealing at temperature higher than 650 degrees C induces a transformation from the chemically disordered fcc Al phase to the L1(0) chemically ordered phase. The nanoparticle shape evolution and the mechanism of the disorder-order transformation are discussed. (C) 2007 Elsevier B.V. All rights reserved.

引用

页码：545 / 551

页数：7

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