https://doi.org/10.1140/epjb/e2005-00202-8
Magnetic nanoscale aggregates of cobalt and nickel in MgO single crystals
1
Dep. de Física/CFMC-UL, FCUL, Campo Grande, Ed. C8,
1749-016 Lisboa, Portugal
2
LFI, Dep. de Física, ITN, E.N.10
2686-953 Sacavém, Portugal
3
Dep. de Física/FCT-UNL,
Monte da Caparica, 2829-516 Caparica, Portugal
4
CFNUL,
Av. Prof. Gama Pinto 2, 1649-003 Lisboa, Portugal
5
Dep. de
Física, Universidad Carlos III, 28911 Leganés (Madrid),
Spain
Corresponding author: a mmcruz@fc.ul.pt
Received:
3
March
2005
Revised:
11
April
2005
Published online:
6
July
2005
The magnetic properties of Co and Ni nanosized aggregates formed after implantation of nickel and cobalt ions in magnesium oxide single crystals were investigated. The influence of the implantation energy and annealing treatments was characterized. The particle size distribution was determined from the combined analysis of the magnetic moment dependence on both magnetic field and temperature, and used to determine the magnetic anisotropy constant of the aggregates. The results for nickel aggregates indicate the presence of an antiferromagnetic layer after the annealing treatments.
PACS: 75.50.Tt – Fine-particle systems; nanocrystalline materials / 61.72.Ww – Doping and impurity implantation in other materials / 75.50.Dd – Nonmetallic ferromagnetic materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005
