| Grant number: | 16/21371-5 |
| Support type: | Regular Research Grants |
| Duration: | April 01, 2017 - September 30, 2019 |
| Field of knowledge: | Physical Sciences and Mathematics - Physics - Condensed Matter Physics |
| Principal Investigator: | Luiz Carlos Camargo Miranda Nagamine |
| Grantee: | Luiz Carlos Camargo Miranda Nagamine |
| Home Institution: | Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil |
| Assoc. researchers: | Enio Lima Júnior ; Fermin Fidel Herrera Aragón ; Flavio Garcia ; Giancarlo Espósito de Souza Brito ; José Antonio Huamaní Coaquira ; Roberto Daniel Zysler |
Abstract
This project proposes the synthesis, structural/morphological and magnetic characterizations of the MFe3-xO4 ferrites (M=Co, Mg, Cu or Zn) and In-Sn-O (ITO) (doped with transition and rare-earth elements) nanoparticles. These nanoparticles will be prepared by the thermal decomposition from the metal precursors and the polymeric precursors methods, respectively. In this work, the samples will be characterized by Mössbauer Spectroscopy (MS) with external magnetic field applied up to 14 teslas. This technique will have an essential role in this study since it will give the possibility to know what crystallographic sites (A, B of the ferrite) the iron and the M elements occupy in the compound. It will be also possible to identify the existence of a possible core-shell behavior. The magnetic hyperthermia of the ferrofluid prepared by the ferrite nanoparticles will be studied as a function of the size and the effective anisotropy of them (obtained from the magnetic characterization). These data will be interpreted taking into account the results obtained from the MS analyses. Thereby, we will try to find the optimum concentration (x) and size of the ferrites to improve the heat absorption and, as consequence, the hyperthermia properties of the ferrofluid. In the case of the doped ITO nanoparticles, the hyperfine parameters obtained from the MS (using a Sn radiation source) may help us interpret the magnetic, optic and transport properties that occur in these systems (e.g., oxide-diluted magnetic semiconductor). Then, we will try to find the best doping concentrations of the transition or rare-earth elements to improve the magnetic/electric properties of these compounds, aiming to define the essential properties required for the utilization of these nanoparticles as the main component for the fabrication of new gas sensors. (AU)