Espectroscopia Raman e UV-Vis de amostras de cianita natural
Data
2023-12-15
Autores
Teixeira, Francielle Gonçalves 
Orientadores
Kunzel, Roseli
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A caracterização de minerais naturais tem motivado diversas publicações e tem mobilizado pesquisadores de diferentes áreas e é responsável por avanços científicos e tecnológicos. Este trabalho teve como propósito estudar as propriedades ópticas e vibracionais de amostras de cianita natural azul e verde obtidas comercialmente e provenientes de Minas Gerais. As amostras em bruto foram pulverizadas e posteriormente analisadas por meio dos espectros de absorção óptica (UV-Vis), espectroscopia Raman e Fluorescência Raios X (FRX). Os dados de fluorescência de raios X evidenciaram a presença dos principais componentes presentes nas amostras de cianita que se devem ao Silício, Alumínio (Al), Ferro (Fe) e Titânio (Ti). As amostras de cianita verde também mostraram picos de raios X característicos do Cromo (Cr) e Cálcio (Ca), enquanto nas amostras de cianita azul foi possível observar a presença de Vanádio (V) e Níquel (Ni). Os dados de FRX também evidenciam uma maior concentração de Ferro nas amostras de cianita verde em comparação a amostra de cianita azul. Na espectroscopia Raman foi possível observar bandas de vibração características do grupo (SiO₄)-4 e ligações Al-O, observado nos compostos Al₂SiO₅. Os espectros obtidos para a cianita azul e verde obtidos neste trabalho são similares, mostrando apenas pequenas diferenças nas intensidades de algumas bandas. O espectro Raman para a cianita azul foi comparado a um espectro característico para esse mineral disponível na página do projeto RRUFF para minerais e mostraram boa concordância, indicando que as amostras estudadas neste trabalho correspondem a cianita. A espectroscopia UV-VIS forneceu informações sobre as bandas de absorção na cianita azul e verde e os fenômenos responsáveis pela coloração. Esse estudo também proporcionou compreender e a ver a Física Moderna através da Física Experimental.
The Characterization of natural minerals has motivated several publications and is responsible for scientific and technological advances. This work aimed to study the optical and vibrational properties of blue and green natural kyanite samples obtained commercially and from Minas Gerais. The raw samples were pulverized and analyzed using optical absorption spectra (UV-Vis), Raman spectroscopy, and X-ray fluorescence (XRF). XRF data showed the presence of the main components present in the kyanite samples, which are Silicon, Aluminum (Al), Iron (Fe), and Titanium (Ti). Green kyanite samples also showed X-ray peaks characteristic of Chromium (Cr) and Calcium (Ca), while blue kyanite samples showed the presence of Vanadium (V) and Nickel (Ni). XRF data also showed a higher concentration of Iron in green kyanite samples than in blue kyanite samples. Raman's spectroscopy shows characteristic vibration bands of the (SiO₄)4- group and Al-O bonds observed in Al₂SiO₅ compounds. The spectra registered for blue and green kyanite in this work are similar, showing only minor differences in the intensities of some bands. The Raman spectrum for blue kyanite was compared to a characteristic spectrum for this mineral available on the RRUFF project website and showed good agreement with the samples studied in this work. UV-VIS spectroscopy provided information on the absorption bands in blue and green kyanite and the phenomena responsible for the coloration. This study also allowed us to understand Modern Physics through Experiments.
The Characterization of natural minerals has motivated several publications and is responsible for scientific and technological advances. This work aimed to study the optical and vibrational properties of blue and green natural kyanite samples obtained commercially and from Minas Gerais. The raw samples were pulverized and analyzed using optical absorption spectra (UV-Vis), Raman spectroscopy, and X-ray fluorescence (XRF). XRF data showed the presence of the main components present in the kyanite samples, which are Silicon, Aluminum (Al), Iron (Fe), and Titanium (Ti). Green kyanite samples also showed X-ray peaks characteristic of Chromium (Cr) and Calcium (Ca), while blue kyanite samples showed the presence of Vanadium (V) and Nickel (Ni). XRF data also showed a higher concentration of Iron in green kyanite samples than in blue kyanite samples. Raman's spectroscopy shows characteristic vibration bands of the (SiO₄)4- group and Al-O bonds observed in Al₂SiO₅ compounds. The spectra registered for blue and green kyanite in this work are similar, showing only minor differences in the intensities of some bands. The Raman spectrum for blue kyanite was compared to a characteristic spectrum for this mineral available on the RRUFF project website and showed good agreement with the samples studied in this work. UV-VIS spectroscopy provided information on the absorption bands in blue and green kyanite and the phenomena responsible for the coloration. This study also allowed us to understand Modern Physics through Experiments.