Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: DEYVID DO CARMO SILVA
DATA: 18/02/2021
HORA: 14:30
LOCAL: Sala virtual
TÍTULO: Laser sintering and influence of the Dy concentration on BaAl2O4:Eu2+,Dy3+
persistent luminescence ceramics
PALAVRAS-CHAVES: Laser sintering, barium aluminate, persistent luminescence
PÁGINAS: 6
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
SUBÁREA: Física da Matéria Condensada
ESPECIALIDADE: Prop. Óticas e Espectrosc. da Mat. Condens; Outras Inter. da Mat. com Rad. e Part.
RESUMO:
This work reports the effect of the Dy concentration on the persistence luminescence properties of Eu dopedbarium aluminate (BaAl2O4) laser-sintered ceramics. For this study, the ceramics were first sintered using thelaser sintering technique, based on a CO2 laser as the heating source, in an ambient atmosphere. The structuraland morphology characteristics of the samples were investigated by x-ray diffraction (XRD) and scanningelectron microscopy (SEM) techniques, respectively. The laser-sintered ceramics presented are shown to be phasepure (single phased), and, for highest Dy concentration sample, a spurious Dy-rich phase at the grain boundarywas observed. All samples exhibit the characteristic blue-green emission from the Eu2+ ion, due to the 4f65d1–4f7transition (495 nm), even when they have been sintered in air. Finally, a clear dependence of the persistentluminescence intensity and decay time with the Dy concentration was verified.