Estudio experimental y computacional por DFT de propiedades estructurales, ópticas y magnéticas de nanopartículas de Fe3O4 y CoFe2O4 sintetizadas por co-precipitación
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Date
2024
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Universidad Nacional de Trujillo
Abstract
Se realizó un estudio computacional utilizando simulaciones basadas en la teoría del funcional deladensidadparalasestructurasdeFe3O4 y CoFe2O4. Se encontró que los estados fundamentales magnéticos y catiónicos de ambos compuestos son anti ferromagnéticos con una distribución catiónica dispersa. El estudio de la estructura electrónica reveló las transiciones ópticas representativas de los electrones mayoritarios y minoritarios, determinando el comportamiento half-metallic de la Fe3O4 y el comportamiento semiconductor de la CoFe2O4. Adicionalmente, los cálculos de fonones determinaron los modos principales y las regiones vibracionales de cada material. Asimismo, se llevó acabo un estudio experimental de las propiedades estructurales, ópticas y magnéticas de las nanopartículas de Fe3O4 y CoFe2O4 sintetizadas por el método deco-precipitación a diferentes tiempos de reacción (0,15,30 y 45minutos). Para ello, se caracterizaron sus propiedades estructurales mediante difracción de rayos X, dispersión de luz dinámica, microscopía electrónica de barrido, espectroscopía infrarroja por transformada de Fourier y espectroscopía Raman. Las propiedades ópticas se analizaron mediante espectroscopía de reflectancia difusa, y las propiedades magnéticas mediante magnetometría de muestra vibrante. Se determinó e lcrecimiento del tamaño de las nanopartículas con respecto al tiempo de reacción, encontrándose super paramagnetismo en las nanopartículas de Fe3O4. Además, se estableció que el tiempo de reacción óptimo para aplicación es biomédicas es de 30 minutos
Abstract A computational study was conducted using density functional theory (DFT) simulations on the structures of Fe 3O4 and CoFe2O4. Themagnetic and cationic ground states of both compounds were found to be antiferromagnetic with a dispersed cationic distribution.The study of the electronic structure revealed the representative optical transitions of majority and minority electrons, determining the half-metallic behavior of Fe3O4 and the semiconductor behavior of CoFe2O4. Additionally, phonon calculations identified the main modes and vibrational regions of each material. An experimental study was also carried out on the structural, optical, and magnetic properties of Fe3O4 and CoFe2O4 nanoparticles synthesized via theco-precipitation method at different reaction times (0,15,30,and 45 minutes). The structural properties were characterized using X ray diffraction, dynamic light scattering, scanning electron microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy. Optical properties were analyzed through diffuse reflectance spectroscopy, and magnetic properties were examined using vibrating sample magnetometry. It was determined that nanoparticle size increased with reaction time, with superparamagnetism observed in the Fe3O4 nanoparticles. Furthermore, the optimal reaction time for biomedical applications was established to be 30 minutes.
Abstract A computational study was conducted using density functional theory (DFT) simulations on the structures of Fe 3O4 and CoFe2O4. Themagnetic and cationic ground states of both compounds were found to be antiferromagnetic with a dispersed cationic distribution.The study of the electronic structure revealed the representative optical transitions of majority and minority electrons, determining the half-metallic behavior of Fe3O4 and the semiconductor behavior of CoFe2O4. Additionally, phonon calculations identified the main modes and vibrational regions of each material. An experimental study was also carried out on the structural, optical, and magnetic properties of Fe3O4 and CoFe2O4 nanoparticles synthesized via theco-precipitation method at different reaction times (0,15,30,and 45 minutes). The structural properties were characterized using X ray diffraction, dynamic light scattering, scanning electron microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy. Optical properties were analyzed through diffuse reflectance spectroscopy, and magnetic properties were examined using vibrating sample magnetometry. It was determined that nanoparticle size increased with reaction time, with superparamagnetism observed in the Fe3O4 nanoparticles. Furthermore, the optimal reaction time for biomedical applications was established to be 30 minutes.
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Keywords
Nanopartículas, DFT, coprecipitación, Propiedades estructurales,
Propiedades ópticas, Propiedades magnéticas, Fe3O4 , CoFe2O4.