The internal structure of magnetic nanoparticles determines the magnetic response

0476778 - FZÚ 2018 RIV GB eng J - Článek v odborném periodiku
Pacáková, Barbara - Kubíčková, Simona - Salas, G. - Mantlíková, Alice - Marciello, M. - Morales, M.P. - Nižňanský, D. - Vejpravová, Jana
The internal structure of magnetic nanoparticles determines the magnetic response.
Nanoscale. Roč. 9, č. 16 (2017), s. 5129-5140. ISSN 2040-3364. E-ISSN 2040-3372
Grant CEP: GA ČR(CZ) GA15-01953S
Institucionální podpora: RVO:68378271
Klíčová slova: nanoparticles * single-domain * internal structure
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 7.233, rok: 2017

This work aims to emphasize that the magnetic response of single-domain magnetic nanoparticles (NPs) is driven by the NPs’ internal structure, and the NP size dependencies of magnetic properties are overestimated. The relationship between the degree of the NPs’ crystallinity and magnetic response is unambiguously demonstrated in eight samples of uniform maghemite/magnetite NPs and corroborated with the results obtained for about 20 samples of spinel ferrite NPs with different degrees of crystallinity. The NP samples were prepared by the thermal decomposition of an organic iron precursor subjected to varying reaction conditions, yielding variations in the NP size, shape and relative crystallinity. We characterized the samples by using several complementary methods. We evaluated the NPs’ relative crystallinity by comparing the NP sizes determined from TEM and PXRD and further inspecting the NPs’ internal structure and relative crystallinity by using HR-TEM. The results of the structural characterization were put in the context of the NPs’ magnetic response. Our results clearly demonstrate that the NP crystallinity level that is mirrored in the internal spin order drives the specific magnetic response of the single-domain NPs.
Trvalý link: http://hdl.handle.net/11104/0273197