Influence of aggregate coating on relaxations in the systems of iron oxide nanoparticles

0386310 - FZÚ 2013 RIV SG eng J - Článek v odborném periodiku
Bittová, Barbara - Poltierová Vejpravová, Jana - Del Morales, M.P. - Roca, A.G. - Nižňanský, D. - Mantlíková, Alice
Influence of aggregate coating on relaxations in the systems of iron oxide nanoparticles.
Nano. Roč. 7, č. 1 (2012), s. 1-10. ISSN 1793-2920. E-ISSN 1793-7094
Grant CEP: GA ČR GAP108/10/1250
Výzkumný záměr: CEZ:AV0Z10100520
Klíčová slova: magnetic nanoparticles * aggregates * inter-particle interactions * coating * relaxation time
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 1.167, rok: 2012

We have investigated properties of systems of strongly interacting magnetic nanoparticles in order to estimate the influence of the inter-aggregate interactions on the collective phenomena. We have compared two systems composed of γ-Fe2O3 nanoparticles, prepared by thermal decomposition of an organic precursor and coprecipitation, respectively; with those prepared by coprecipitation, containing the particle aggregates coated by SiO2 layer of different thickness. Detailed magnetic studies of all samples such as the temperature dependence of magnetization and frequency dependent a.c.susceptibility,recorded also in external magnetic field,revealed the blocking temperature closeto 300K and super-spinglass(SSG) or SSG-like nature of the systems. The slight minimization of the interaction strength in the system with increasing thickness of the SiO2 coating has been observed.
Trvalý link: http://hdl.handle.net/11104/0215593