Banca de DEFESA: JULIANE GERMANO DE SOUZA GONDIM

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : JULIANE GERMANO DE SOUZA GONDIM
DATA : 27/07/2018
HORA: 15:00
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

STUDY OF THE PHOTOLUMINESCENT PROPERTIES OF CALCIUM ALUMINATE DOPED WITH THE EUROpio III.

PALAVRAS-CHAVES:

Calcium aluminate, europium, photoluminescent, Sol-Gel method, 1, 4-butanediol.

PÁGINAS: 72
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

Luminescent materials have been widely applied in many areas, such as illumination, movies, artificial fibers, painting, optical markers and others. Among luminous materials, aluminates have been showed its quality, even more when they are doped or codoped with rare soil, due to its great chemical and thermal stability, not forgetting its lasting photoluminescent property. In this paper, structural and optical behaviors of calcium aluminate doped with europium III (Ca1-xEuxAl2O4 with x = 0%, 1%, 2% and 4% mole) were studied. The formulations were synthesized through sol-gel method and calcined at 1300°C and 1500°C, with fractions of deionized water and 1, 4-butanediol (diol) on its medium of reaction. Those parameters affected the crystalline structure, and the photocatalytic and luminescent properties of each sample. The x-ray diffraction (XRD) indicated the obtention of the desired phase and with great crystallinity on both temperatures, but the lowest temperature indicated secondary phases formation. The scanning electron microscopy (SEM) indicated that temperature increase makes the three-dimensional morphology become more compact and with a high degree sintering. The increase in fractions of europium in the diol reactional medium made the particles presente a significant reduction on its size. On photocatalytic activity, the referred addition was unsatisfactory because the samples that indicated a higher influence on dyes degradation were the base samples with 0% of diol on the reaction and 0% of europium element. The sample’s photoluminescent spectra indicated narrows and well-defined bands that are characteristics of europium element transitions. They also indicate that the increase in fraction of both dopant and diol generated a photoluminescent properties increment and a photocatalysis reduction. The increase also affects samples’ color emission. On this paper, it was possible to evaluate that the base samples presented bluish and greenish colorations, and with the increase, mainly of europium, they presented warmer colorations that went from orange to red.

MEMBROS DA BANCA:
Externo à Instituição - BRAULIO SILVA BARROS - UFPE
Interno - 1300987 - CARLOS ALBERTO PASKOCIMAS
Presidente - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE