https://doi.org/10.1007/s100530170238
Phase transitions in Co nanoclusters grown by pulsed laser deposition
Laboratoire de Minéralogie-Cristallographie de Paris (UMR 7590 du CNRS) , Universités Paris 6 et Paris 7,
case 115, 4 place Jussieu, 75252 Paris Cedex 05, France
Corresponding author: a ricollea@lmcp.jussieu.fr
Received:
3
July
2000
Revised:
22
December
2000
Published online: 15 April 2001
The crystalline structure of Co clusters embedded in an amorphous Al2O3 matrix was studied
by transmission electron microscopy (TEM) and electron diffraction (TED). In the first stage
of the growth a metastable structure (body-centred-cubic) is observed. A face-centred-cubic
phase (fcc) is found when the size of the clusters increases (
nm). The hexagonal-close-packed phase arises in the fcc phase by a succession of stacking faults at the largest sizes. The mechanisms of phase transformation have been determined by using high
resolution electron microscopy (HREM). The chemical nature of the clusters, in particular the
existence of Co-O bonds, was investigated by using electron energy loss spectroscopy
(EELS).
PACS: 61.46.+w – Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals / 61.16.Bg – Transmission, reflection and scanning electron micrography (including EBIC) / 61.50.Ks – Crystallographic aspects of phase transformations; pressure effects
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001
