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Correlation of Electronic and Magnetic Properties of Thin Polymer Layers with Cobalt Nanoparticles
Author(s) -
Kharchenko Andrej,
Lukashevich Mikhail,
Popok Vladimir,
Khaibullin Rustam,
Valeev Valerij,
Bazarov Valerij,
Petracic Oleg,
Wieck Andreas,
Odzhaev Vladimir
Publication year - 2013
Publication title -
particle and particle systems characterization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 56
eISSN - 1521-4117
pISSN - 0934-0866
DOI - 10.1002/ppsc.201200042
Subject(s) - nucleation , fluence , materials science , superparamagnetism , cobalt , magnetoresistance , nanoparticle , ferromagnetism , percolation (cognitive psychology) , nanocomposite , condensed matter physics , ion , polymer , scattering , magnetic nanoparticles , magnetization , chemical physics , nanotechnology , magnetic field , chemistry , composite material , optics , physics , organic chemistry , quantum mechanics , neuroscience , metallurgy , biology
Nanoparticles (NPs) of cobalt are synthesized in shallow layers of polyimide using 40 keV implantation of Co + ions with a few different fluences at various ion current densities. Nucleation of individual NPs at low fluencies and their percolation at high fluencies are crucial processes governing the electrical and magnetic properties of the metal/polymer nanocomposites that can be controlled by the implantation regimes. In particular, one can tune the magnetoresistance between negative and positive through appropriate choice of ion fluence and current density. The found non‐monotonous dependence of the magnetoresistance on the applied magnetic field allows suggestion of spin‐dependent domain wall scattering affecting the electron transport. The samples implanted with low fluencies demonstrate superparamagnetic behavior down to very low blocking temperatures. For high fluence (1.25 × 10 17 cm −2 ) the transition to ferromagnetic ordering is observed that is related to the increased magnetic interaction of NPs.