Banca de QUALIFICAÇÃO: ALICIANE CÍNTIA MAIA GAMA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : ALICIANE CÍNTIA MAIA GAMA
DATA : 31/07/2018
HORA: 14:30
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

Synthesis and characterization of the mixed oxide (La2-xFex)Ce2O7 from the EDTA-Citrate combined complexation method

PALAVRAS-CHAVES:

La2Ce2O7, EDTA-Citrate, crystallite size, band gap.

PÁGINAS: 66
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

This work had as objective to synthesis of La2Ce2O7 pure and Fe-doped (La2-xFex)Ce2O7, x = 1, from the EDTA-Citrate combined complexation method. For the synthesis of powders were used reagents with oxidation state Ce3+ and Ce4+. Calcination temperatures taken in getting the La2Ce2O7 and phases (La2-xFex)Ce2O7, x = 1, were 550, 725, 900 and 1000° C, and 500, 675 and 850 ºc, respectively. The materials obtained have been characterized by x-ray diffraction (DRX), Rietveld refinement, scanning electron microscopy (SEM) and diffuse reflectance spectroscopy. There was the formation of two phases (LaFeO3 e CeO2) when the La2Ce2O7 pure was doped with Fe, LaFeO3 this phase in greater quantity (59%), and to a lesser extent CeO2 (41%). The synthesis of (La2-xFex)Ce2O7, x = 1, with the Ce4+ and calcination temperature equal to 850° C produced powders with smaller average crystallite size and lower band gap energy.

MEMBROS DA BANCA:
Presidente - 349801 - CARLSON PEREIRA DE SOUZA
Externo à Instituição - FRANCISCO WENDELL BEZERRA LOPES - UnP
Externo ao Programa - 338292 - JOAO BOSCO LUCENA DE OLIVEIRA