Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/107006
Title: Manifestation of coherent magnetic anisotropy in a carbon nanotube matrix with low ferromagnetic nanoparticle content
Author: Danilyuk, A. L.
Komissarov, I. V.
Labunov, V. A.
Le Normand, F.
Derory, A.
Hernández Ferràs, Joan Manel
Tejada Palacios, Javier
Prischepa, S. L.
Keywords: Nanotubs
Carboni
Nanopartícules
Anisotropia
Nanotubes
Carbon
Nanoparticles
Anisotropy
Issue Date: 2015
Publisher: Institute of Physics Pub.
Abstract: The influence of the magnetic medium can lead to peculiar interaction between ferromagnetic nanoparticles (NPs). Most research in this area involves analysis of the interplay between magnetic anisotropy and exchange coupling. Increasing the average interparticle distance leads to the dominant role of the random magnetic anisotropy. Here we study the interparticle interaction in a carbon nanotube (CNT) matrix with low ferromag netic NP content. Samples were synthesized by fl oating catalyst chemical vapor deposition. We fo und that below some critical NP concentration, when NPs are intercalated only inside CNTs, and at low temperatures, th eextendedmagnetic order, of up to 150 nm, presents in our samples. It is shown by analyzing the correlation functions of the magnetic anisotropy axes that the extended order is not simply due to random anisotropy but is associated with the coherent magnetic anisotropy, which is strengthened by the CNT alignment. With increasing temperature the extended magnetic order is lost. Above the critical NP concentration, when NPs start to be intercalated not only into inner CNT channels, but also outside CNTs, the coherent anisotropy weakens and the exchange coupling dominates in the whole temperature range. We can make a connection with the various correlation functions using the generalized expression for the law of the approach to saturation and show that these different correlation functions re fl ect the peculiarities in the interparticle interaction inside CNTs. Moreover, we can extract such important micromagnetic parameters like the exchange field, local fields of random and coherent anisotropies, as well as their temperature and NP concentration dependencies.
Note: Reproducció del document publicat a: https://doi.org/10.1088/1367-2630/17/2/023073
It is part of: New Journal of Physics, 2015, vol. 17, p. 023073
Related resource: https://doi.org/10.1088/1367-2630/17/2/023073
URI: http://hdl.handle.net/2445/107006
ISSN: 1367-2630
Appears in Collections:Articles publicats en revistes (Física de la Matèria Condensada)

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