1
artículo
Publicado 2020
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Dysprosium (Dy3+)-doped tin oxide (SnO2) nanoparticles (NPs) have been successfully synthesized using the chemical polymer precursor method. This material blends the holding matrix’s electronic properties with dysprosium’s optical and magnetic properties, making it a promising material for technological applications. X-ray diffraction patterns and the Raman spectra of all NPs indicated the formation of only the SnO2 phase. The decrease in particle size (from ~ 11 to ~ 6 nm) and increase in lattice parameters depending on the Dy content were determined. The latter proves the solid solution between Sn and Dy ions, which is in agreement with the ionic radii mismatch between them. Transmission electron microscopy (TEM) confirms the particle size and size reduction observed through XRD. X-ray photoelectron spectroscopy (XPS) results suggest a change of the oxidation state from Sn4+ to Sn2...
2
artículo
Publicado 2021
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Magnetite (Fe3O4) nanoparticles coated with organic material are of considerable importance in various areas of engineering, as well as in biomedicine. Several papers show drastic changes in the magnetic properties related to the surface effects and the particle-particle interactions strength. However, there is no consensus about the origin or mechanisms that produce these changes, which could be different depending on the particle size and shape, coating efficiency and particle-particle interaction strength. Aiming to shed light on these issues, oleic acid (OA) coated Fe3O4 nanoparticles with different sizes were synthesized by a thermal decomposition method. Structural and microscopic results revealed Fe3O4 nanoparticles with good crystallinity and almost-spherical or polyhedral shapes depending on the solvent used for the synthesis. Infrared (FTIR) spectroscopy indicated OA molecules ...
3
artículo
Publicado 2021
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During the last decade, there was a substantial increase in the research on metal-doped oxide semiconductor nanoparticles due to advances in the engineering of nanomaterials and their potential application in spintronics, biomedicine and photocatalysis fields. In this regard, doping a nanomaterial is a powerful tool to tune its physicochemical properties. The aim of this work is to shine a new light on the role of the neighbouring elements on the oxidation state of the Ce-impurity, from both experimental and theoretical points of view. Herein, we present an accurate study of the mechanisms involved in the oxidation states of the Ce-ions during the doping process of SnO2nanoparticles (NPs) prepared by the polymeric precursor method. X-ray diffraction measurements have displayed the tetragonal rutile-type SnO2phase in all samples. However, the Bragg’s peak (111) and (220) located at 2??2...
4
artículo
Publicado 2021
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Fe-doped indium tin oxide (ITO) is an exciting material because it combines the host matrix's good electrical conductivity with the magnetic properties coming from the most earth-abundant transition metal, Fe. In this regard, a single-pot synthesis route based on a polymeric precursor method has been used to produce high-quality undoped and iron-doped ITO with iron content up to 13.0 mol%. The crystal formation in the bixbyite-type structure of all samples is confirmed by X-ray diffraction data analysis. A monotonous decrease of the lattice parameters with the increase of the Fe content is determined, which is consistent with of Fe ions with an oxidation state of 3+ in agreement with the ionic radii difference between In3+ and Fe3+. Raman spectroscopy confirms the bixbyite structure formation and provides evidence of a high surface disorder. 119Sn Mössbauer spectroscopy reveals the form...