Banca de DEFESA: LUCAS BATISTA SILVA LIMA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: LUCAS BATISTA SILVA LIMA
DATA: 31/05/2022
HORA: 14:30
LOCAL: Remota
TÍTULO: Avaliação das propriedades termo-ópticas de vidros de GeO 2 – Bi 2 O 3 dopados com Er 3+ por espectroscopia de lente térmica
PALAVRAS-CHAVES: Termo-ópticas, Lente térmica, terras raras, vidros dopados, eficiência quântica, fluorescência.
PÁGINAS: 55
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
RESUMO:

Materials doped with rare earths have been of great interest due to
their photoluminescence properties, visible, ultraviolet and near infrared
absorption bands which combined with the low non-radioactive loss of
germanium oxide and bismuth oxide glasses make them promising for photonic
applications. Here in this work, was investigated the optical and thermo-optical
properties of glass matrices of GeO 2 – Bi 2 O 3 doped with valence 3+ erbium ions
at concentrations of 0.1%, 0.25%, 0.75% and 1%, through thermal lens (LT),
UV-Vis and fluorescence spectroscopy techniques. The diffusivity ranged from
2.25x10 -3 cm 2 /s to 2.32 x10 -3 cm 2 /s for the different concentrations, indicating
that doping does not alter the heat diffusion. The absorption spectrum showed
peaks referring to the transitions from the 4 I 15/2 ground state to the excited states
of Er 3+ that are intensified with increasing concentration. Likewise, the peaks in
the emission spectrum, 545 nm and 652 nm, were intensified with increasing
concentration. And finally, the samples had quantum fluorescence efficiency
results of 84% for the lowest concentration and 74% for the highest
concentration. So, based on the results, the glasses of GeO2 – Bi2O3 doped
with 0.1% of good prospects in the production of fluorescent material.

MEMBROS DA BANCA:
Presidente - 1780191 - FRANCISCO ERONI PAZ DOS SANTOS
Interno - 2056226 - CLEANIO DA LUZ LIMA
Interno - 2092477 - HANS ANDERSON GARCIA MEJIA
Interno - 1650556 - TAYRONI FRANCISCO DE ALENCAR ALVES
Externo à Instituição - LUCIANA REYES PIRES KASSAB - FATEC