Banca de DEFESA: CRISTOVAO PORCIANO DO NASCIMENTO JUNIOR

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : CRISTOVAO PORCIANO DO NASCIMENTO JUNIOR
DATA : 14/09/2017
HORA: 10:00
LOCAL: Auditório do DFTE
TÍTULO:

Synthesis, Structural and dielectric characterization of iron niobate.

PALAVRAS-CHAVES:

Iron niobate. Dielectric characterization. Thyristor. Permittivity.

PÁGINAS: 93
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
SUBÁREA: Física da Matéria Condensada
RESUMO:

Iron niobate (FeNbO4) has been applied to the photodiode in solar energy converters,
gas sensors, photo detectors, and electronic devices. However, a full description of your
dielectric properties is still scarceness so. By using a high energy mill, was prepared three
kinds of samples (24, 48 and 72 hours) of precursors. After milling process, the resultant
ponders were to calcinate for precisely 4 hours and in a temperature of 1 300 celsius.
We used a hydraulic press about 1570 Kgf to produce samples. Next, samples were calcinated during a time considered the same for all of them and underwent to dielectric
characterization. In the way to characterize the samples, the formers were submitted to
X rays, scanning electronic microscopy and X rays uorescence. Results have been shown
that samples milling by 24 hours, has 94.48% of FeNbO4 and 5.52% of Fe2O3, by 48h
has 97.82% of FeNbO4 and 2,18% de Fe2O3, and by 72h 93,68% of FeNbO4 and 6.32% of
Fe2O3. Dielectric properties were analyzed through I-V characteristic curves and complex
dialectic permitivity against frequency. Characteristic curves exhibited semiconductors
electronic devices behave like thyristor class. Furthermore, actual work constitutes a fully
new route to sintering iron niobate. Results still indicated the samples have potential
application in the electronic devices.

MEMBROS DA BANCA:
Interno - 2199774 - CARLOS CHESMAN DE ARAUJO FEITOSA
Externo à Instituição - SERGIO ANDRÉ FONTES AZEVEDO - UFPB
Presidente - 1675199 - SUZANA NOBREGA DE MEDEIROS
Externo à Instituição - TIBERIO MAGNO DE LIMA ALVES - IFRN
Externo ao Programa - 345842 - UILAME UMBELINO GOMES