fcc-hcp phase transformation in Co nanoparticles induced by swift heavy-ion irradiation

被引：33

作者：

Sprouster, D. J. ^{[1
]}

Giulian, R. ^{[1
]}

Schnohr, C. S. ^{[1
]}

Araujo, L. L. ^{[1
]}

Kluth, P. ^{[1
]}

Byrne, A. P. ^{[2
]}

Foran, G. J. ^{[3
]}

Johannessen, B. ^{[3
]}

Ridgway, M. C. ^{[1
]}

机构：

[1] Australian Natl Univ, Dept Elect Mat Engn, Res Sch Phys & Engn, Canberra, ACT 0200, Australia

[2] Australian Natl Univ, Dept Phys, Fac Sci, Canberra, ACT 0200, Australia

[3] Australian Nucl Sci & Technol Org, Menai, NSW 2234, Australia

来源：

PHYSICAL REVIEW B | 2009年 / 80卷 / 11期

基金：

澳大利亚研究理事会;

关键词：

COBALT NANOCRYSTALS; MAGNETIC-PROPERTIES; SILICA GLASS; NANOCLUSTERS; IMPLANTATION; METALS; TEMPERATURE; TRACKS; PURE;

D O I：

10.1103/PhysRevB.80.115438

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We demonstrate a face-centered cubic (fcc) to hexagonally close-packed (hcp) phase transformation in spherical Co nanoparticles achieved via swift heavy-ion irradiation. Co nanoparticles of mean diameter 13.2 nm and fcc phase were first formed in amorphous SiO2 by ion implantation and thermal annealing and then irradiated at room temperature with 9-185 MeV Au ions. The crystallographic phase was identified with x-ray absorption spectroscopy and electron diffraction and quantified, as functions of the irradiation energy and fluence, with the former. The transformation was complete at low fluence prior to any change in nanoparticle shape or size and was governed by electronic stopping. A direct-impact mechanism was identified with the transformation interaction cross-section correlated with that of a molten ion track in amorphous SiO2. We suggest the shear stress resulting from the rapid thermal expansion about an ion track in amorphous SiO2 was sufficient to initiate the fcc-to-hcp phase transformation in the Co nanoparticles.

引用

页数：5

共 47 条

[1] Elongation of gold nanoparticles in silica glass by irradiation with swift heavy ions [J].