Coercivity dependence of cation distribution in Co-based spinel: Correlating theory and experiments
Autor
Melo Freire, Rafael
Palma, Juan Luis
Sebastián A., Michéa
Ramírez, Ricardo
Baltazar, Samuel E.
Casagrande Denardin, Juliano
Resumen
The inversion degree (X) of a spinel-type nanomaterial is an essential parameter to understand the magnetic and electronic properties of ferrites. In this work, we have related different theoretical and experimental approaches in order to know the X parameter of a Co-based spinel. Our hypothesis is that the hysteresis curve at 5 K may be used to find the X parameter taking into consideration that the coercivity and remanence of this kind of nanoparticle (NP) are strongly dependent on the cation distribution between A and B sites of the spinel structure. To investigate this, CoFe2O4 NPs were firstly synthesized and fully characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). These results pointed out monodisperse CoFe2O4 nanostructures with a spherical shape of 6.85 ± 0.05 nm. Subsequently, first-principles calculations were carried out to obtain the most stable atomic configuration as a function of the level of inversion, as well as the atomic properties for each X. Then, these data were used to define the constants used in the micromagnetic calculations. A hysteresis loop was generated for each X and further compared to the experimental curve measured at 5 K. In this sense, the best fit was found for X = 0.75, which indicates this value as the most probable inversion degree for the CoFe2O4 nanostructures investigated in this work. Overall, we are able to connect the experiments with the atomistic explanation through micromagnetic simulations in order to find the cationic configuration of the Co-based spinel nanostructure.
Colecciones
Ítems relacionados
Mostrando ítems relacionados por Título, autor o materia.
-
Book
Natural arrangement of AgCu bimetallic nanostructures through oleylamine reduction (2021)
Melo Freire, Rafael; Rojas-Nunez, Javier; Elias-Arriaga, A.L.; Fujisawa, K.; Troncoso, Loreto; Casagrande Denardin, Juliano; Baltazar, Samuel E. (Royal Society of Chemistry, 2020-12-21)Noble-metal-based catalysts are the most used nanomaterials to carry out electrochemical reactions, which are commonly applied in fuel cells. This kind of catalyst is expensive and it is worth mentioning that noble metals ... -
Article
Starch-based magnetic nanocomposite for targeted delivery of hydrophilic bioactives as anticancer strategy (2021)
Sousa, Alexandre C.C.; Romo, Adolfo I.B.; Almeida, Raimundo R.; Silva, Aiêrta C.C.; Uchoa Dutra Fechine, Lillian Maria; Almeida Brito, Débora Hellen; Melo Freire, Rafael; Pascoalino Pinheiro, Daniel; Ribeiro Da Silva, Larissa Morais; Loiola Pessoa, Otília Deusdênia; ... (Elsevier Ltd, 2021-07-15)Magnetic nanocomposites were synthesized for the targeted delivery of hydrophilic bioactives through guidance generated by a magnetic field. Superparamagnetic iron oxide nanoparticles (SPIONs) were used to generate ... -
Article
From magneto-dielectric biocomposite films to microstrip antenna devices (2021)
de Menezes, Fernando Lima; Andrade Neto, Davino Machado; Linhares Rodrigues, Maria Do Livramento; Silva Lima, Helder Levi; Paiva, D. V.M.; Santos da Silva, Marcelo Antônio; Uchoa Dutra Fechine, Lillian Maria; Bezerra Sombra, Antônio Sérgio; Melo Freire, Rafael; Casagrande Denardin, Juliano; ... (MDPI AG, 2020)Magneto-dielectric composites are interesting advanced materials principally due to their potential applications in electronic fields, such as in microstrip antennas substrates. In this work, we developed superparamagnetic ...