Characterization of $$\text{CoFe}_2$$$$\text{O}_4$$, $$\text{NiFe}_2$$$$\text{O}_4$$, and $$\text{ZnFe}_2$$$$\text{O}_4$$ Nanoparticles Synthesized by a Proteic Sol-gel Method

Autor: L. P. M. Santos, M. P. S. Palácio, Igor F. Vasconcelos, F. G. S. Oliveira, V. M. R. Vasconcelos, M. S. Pereira, D. L. M. Vasconcelos, Paulo Freire
Rok vydání: 2021
Předmět:
Zdroj: Journal of Superconductivity and Novel Magnetism. 34:2845-2853
ISSN: 1557-1947
1557-1939
Popis: Nanoparticles of cobalt, nickel, and zinc spinel ferrites were successfully synthesized by a low-cost method named as proteic sol-gel method, and a comparative study was performed. Commercial metal nitrates and gelatin from bovine skin were used as precursors. Thermogravimetric analysis and differential scanning calorimetry were performed to investigate the thermal behavior of the precursor powders as well as to select the appropriate calcination temperature for oxide formation. Structural, morphological, optical, and magnetic properties were studied by X-ray diffraction, Mossbauer spectroscopy, transmission electron microscopy, vibrating sample magnetometry, Raman spectroscopy, and UV/VIS diffuse reflectance spectroscopy. Spherical nanoparticles with a single cubic spinel structure were obtained. The results indicate that the average particle sizes are less than 10 nm. $$\mathrm{CoFe}_2\mathrm{O}_4$$ and $$\text{NiFe}_2$$ $$\text{O}_4$$ exhibited ferrimagnetic and superparamagnetic behavior simultaneously, whereas $$\text{ZnFe}_2$$ $$\text{O}_4$$ was found to be paramagnetic. The optical band gaps obtained were 1.40, 1.75, and 2.12 eV for $$\mathrm{CoFe}_2\mathrm{O}_4$$ , $$\text{NiFe}_2$$ $$\text{O}_4$$ , and $$\text{ZnFe}_2$$ $$\text{O}_4$$ samples, respectively.
Databáze: OpenAIRE
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