Banca de DEFESA: RAYANE RICARDO DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : RAYANE RICARDO DA SILVA
DATA : 03/03/2017
HORA: 09:00
LOCAL: Sala de Aula PPGCEM
TÍTULO:

Analysis of the synthesis parameters of NbN via gas-solid reaction.

PALAVRAS-CHAVES:

Niobium nitride, gas-solid reaction, fixed bed, Rietveld refinement.

PÁGINAS: 100
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

The aim of this work is to study the synthesis of Niobium Nitride, starting from the precursor tris (oxalate) oxiniobilato ammonium hydrate, through the gas-solid reaction in a fixed-bed reactor. The heat treatment conditions to obtain the NbN were at temperatures 700, 800, 900, 1000 and 1100°C varying the time in the isotherm between 3, 4 and 5 hours. The gas mixture is composed of nitrogen and hydrogen. The composition and the total flow of the gas flow were varied. The obtained materials were characterized by X-ray diffraction (XRD), Rietveld Refinement and Scanning Electron Microscopy (SEM). Increasing the reaction temperature and time in the isotherm it was observed the phase change of niobium oxide to niobium nitride. There was formation of two phases of nitride, and the hexagonal phase is present in greater quantity, and the tetragonal phase in less quantity. These results are not observed in the literature.

MEMBROS DA BANCA:
Externo à Instituição - ANDARAIR GOMES DOS SANTOS - UFERSA
Externo ao Programa - 2929066 - ANDRE LUIS LOPES MORIYAMA
Presidente - 349801 - CARLSON PEREIRA DE SOUZA