Mn-Doping level dependence on the magnetic response of MnxFe3-xO4 ferrite nanoparticles

Autor: Luis Lezama, Aida Serrano, Rosa Martín-Rodríguez, Izaskun Gil de Muro, Maite Insausti, Jesús M. de la Fuente, Xabier Lasheras, Eneko Garaio, José Ángel García, Idoia Castellanos-Rubio, Lourdes Marcano, M. L. Fernández-Gubieda
Přispěvatelé: Ministerio de Economía y Competitividad (España), European Commission, Eusko Jaurlaritza
Rok vydání: 2019
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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Popis: Manganese/iron ferrite nanoparticles with different Mn2+/3+ doping grades have been prepared by a thermal decomposition optimized approach so as to ascertain the doping effect on magnetic properties and, especially, on the magnetic hyperthermia response. The oxidation state and interstitial position of Mn in the spinel structure is found to be critical. The particle size effect has also been studied by growing one of the prepared samples (from 10 to 15 nm in diameter) by a seed mediated growth mechanism. After analyzing the main structural and chemical parameters such as the Mn/Fe rate, crystalline structure, particle diameter, shape and organic coating, some Mn doping induced changes have been observed, such as the insertion of Mn2+ cations yielded more anisotropic shapes. Magnetic characterization, carried out by DC magnetometry (M(H), M(T)) and electron magnetic resonance (EMR) techniques, has shown interesting differences between samples with varying compositions. Lower Mn doping levels lead to larger saturation magnetization values, while an increase of the Mn content causes the decrease of the effective magnetic anisotropy constant at low T. The homogeneous magnetic response under applied magnetic fields, together with the great effect of nanoparticle size and shape in such a response, has been confirmed by the EMR analysis. Finally, a detailed magnetic hyperthermia analysis has demonstrated the large influence of NP size and shape on the magnetic hyperthermia response. The optimized Mn0.13Fe2.87O4_G sample with a diameter of 15 nm and slightly truncated octahedral shape is presented as an interesting candidate for future magnetic hyperthermia mediated biomedical treatments.
This work was supported by institutional funding from the Ministry of Economy and Competitiveness and Basque Government under Projects MAT2016-78266-P (AEI/FEDER, UE) and GIC-IT-570-13.
Databáze: OpenAIRE