Obtenção e caracterização de pós nanoestruturados de CuNb2O6 sintetizados via reação em estado sólido e sol-gel protéico
In recent decades, Brazil has been seeking to expand its research on Niobium, motivated by the potential of its properties, as well as its abundance in our territory. Among these, Copper Niobate (CuNb2O6) has been standing out in science due to its excellent properties for very current technologi...
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| Formato: | Dissertação |
| Idioma: | pt_BR |
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Universidade Federal do Rio Grande do Norte
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| Endereço do item: | https://repositorio.ufrn.br/handle/123456789/52041 |
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| Resumo: | In recent decades, Brazil has been seeking to expand its research on Niobium, motivated by
the potential of its properties, as well as its abundance in our territory. Among these, Copper
Niobate (CuNb2O6) has been standing out in science due to its excellent properties for very
current technological applications such as solar cell devices, microwave devices,
photocathodes, ultrashort pulsed infrared laser sensors, for example. Aiming at this vast
possibility of applications, in this study, therefore, CuNb2O6 nanoparticles were produced
using two routes, with simple methodologies, low cost and that allow obtaining nanoscale
particles, solid state reaction with variation in milling time and gelatin-modified protein
sol-gel using two combinations of precursors, Nb2O5 + CuO e Nb2O5 + Cu(NO3)2
.3H2O. After
obtaining, the powders were calcined in a muffle with temperatures in the range of 500 °C to
1000 °C, for 3 h and heating rate of 5 °C/min. Posteriorly the particles were characterized by
means of X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive
Spectroscopy (EDS) and raman spectroscopy analysis. The results for the solid state reaction
route showed that the increase in milling time led to a reduction in temperature in the
formation of the monoclinic phase, as well as the complete formation of the orthorhombic
phase at the typical temperature of obtaining, in a short time, in addition to an improvement in
the homogeneity of the powder. For the synthesis via protein sol-gel, the XRD results show
that, at 700 °C, the formation of the monoclinic phase begins for both combinations of
precursors, being completely obtained at 900 °C when using CuO. The orthorhombic phase
was obtained completely at 1000 °C in the two combinations of precursors, all samples with
total formation of polymorphs showed good dispersivity. For both routes, the resulting
powders do not contain evidence of contamination, the characteristic particle morphologies
and the raman spectrum are coherent with the literature. The sizes of the crystallites range
from 47 to 75 nm, confirming the nanometric order of the synthesized powders, adding the
observation of their increase proportional to the increase in temperature. |
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