Pechini synthesis and microstructure of nickel-doped copper chromites

Autor: Patrícia Mendonça Pimentel, Antonio Eduardo Martinelli, Dulce Maria de Araújo Melo, Anne Michelle Garrido Pedrosa, Jardel Dantas Cunha, Carlos Neco da Silva Júnior
Jazyk: angličtina
Rok vydání: 2005
Předmět:
Zdroj: Materials Research, Vol 8, Iss 2, Pp 221-224 (2005)
Druh dokumentu: article
ISSN: 1516-1439
DOI: 10.1590/S1516-14392005000200024
Popis: Spinel-type solid solutions were synthesized by the Pechini method and calcined between 500 and 900 °C for 4 hours and at 900 °C for 8 hours to produce ceramic pigments. The resulting powders were characterized by thermogravimetric analysis, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size analysis and BET surface area measurements. The formation of spinel took place upon calcination at 700 °C. IR spectroscopy revealed the presence of n1 and n2 bands, typical of spinel structures, broadened by the presence of more than one cationic species in the structure. The specific area of the resulting powder decreased from 24.7 to 1.4 m² g-1 as the calcination temperature increased from 700 to 900 °C. Microstructural analyses revealed the presence of crystalline spinel as the only phase present in powders calcined at 900 °C. Colorimetric analyses using L*a*b* coordinates and UV-visible spectroscopy revealed that the pigment was predominantly black.
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