Speaker
Mr
Jaianth Vijayakumar
(Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.)
Description
We report the formation and magnetic properties of metallic cobalt-core
and oxide shell structured nanoparticles upon oxidation of Co
nanoparticles with molecular oxygen under ultra-high vacuum conditions.
The presence of a core-shell structure was confirmed with HR-STEM while
x-ray photoemission electron microscopy shows that the core remained
metallic and magnetic at low oxygen dosage, with CoO as the oxide shell.
At higher oxygen dosages CoO and Co3O4 form the oxide shell and the
core loses its magnetic contrast. These results show that the presence of
high magnetic anisotropy in Co nanoparticles does not arise from a surface
anisotropy contribution.
Author
Mr
Jaianth Vijayakumar
(Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.)
Co-authors
Tatiana M. Savchenko
(Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.)
Dr
Armand Béché
(EMAT, University of Antwerp, 2020 Antwerpen, Belgium)
Prof.
Johan Verbeeck
(EMAT, University of Antwerp, 2020 Antwerpen, Belgium)
Prof.
Frithjof Nolting
(Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.)
Dr
Carlos A. F Vaz
(Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.)
Armin Kleibert
(Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.)
