RESUMO
This study aimed to systematically understand the magnetic properties of magnetite (Fe3O4) nanoparticles functionalized with different Pluronic F-127 surfactant concentrations (Fe3O4@Pluronic F-127) obtained by using an improved magnetic characterization method based on three-dimensional magnetic maps generated by scanning magnetic microscopy. Additionally, these Fe3O4 and Fe3O4@Pluronic F-127 nanoparticles, as promising systems for biomedical applications, were prepared by a wet chemical reaction. The magnetization curve was obtained through these three-dimensional maps, confirming that both Fe3O4 and Fe3O4@Pluronic F-127 nanoparticles have a superparamagnetic behavior. The as-prepared samples, stored at approximately 20 °C, showed no change in the magnetization curve even months after their generation, resulting in no nanoparticles free from oxidation, as Raman measurements have confirmed. Furthermore, by applying this magnetic technique, it was possible to estimate that the nanoparticles' magnetic core diameter was about 5 nm. Our results were confirmed by comparison with other techniques, namely as transmission electron microscopy imaging and diffraction together with Raman spectroscopy. Finally, these results, in addition to validating scanning magnetic microscopy, also highlight its potential for a detailed magnetic characterization of nanoparticles.
RESUMO
This manuscript reports room-temperature one-step synthesis of earth-abundant semiconductor ZnSiN2 on amorphous carbon substrates using radio frequency reactive magnetron co-sputtering. Transmission Electron Microscopy and Rutherford Backscattering Spectrometry analysis demonstrated that the synthesis has occurred as ZnSiN2 nanocrystals in the orthorhombic phase, uniformly distributed on amorphous carbon. The technique of large-area deposition on an amorphous substrate can be interesting for flexible electronics technologies. Our results open possibilities for environmentally friendly semiconductor devices, leading to the development of greener technologies.