Banca de DEFESA: LAURA XIMENA LOVISA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : LAURA XIMENA LOVISA
DATA : 09/02/2018
HORA: 14:00
LOCAL: Auditório do CCET
TÍTULO:

Photoluminescent Properties of ZnMoO4 encoded with rare earth ions obtained from the sonochemical method

PALAVRAS-CHAVES:

ZnMoO4: Tm3+ - Tb3+ - Eu3+, Sonochemistry, Photoluminescence

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

A new class of inorganic materials, which emerge as a promising option in high-performance applications in the field of photoluminescence, has gained special attention. This group consists of the molybdates, XMoO4 (X: metal ion), doped with rare earth elements (RE). The characteristics that describe these materials are: high luminous efficiency, long decay time and emission presentation in the visible. In this work ZnMoO4 and ZnMoO4: 1% Tm3+, 1% Tb3+, x Eu3+ (x = 1, 1.5, 2, 2.5 and 3 mol%) particles were synthesized from the sonochemical method. The influence of dopant content and heat treatment on photoluminescent behavior was investigated. The X-ray diffraction results confirmed the formation of α- ZnMoO4 phase with triclinic crystalline structure for the particles. The values of the gap energy are in the range of 3.58 and 4.22 eV. The images of the FE-SEM show an evolution of the morphology of the particles in accordance with the increase of the doping. The morphology of samples are interpreted based on a comparative analysis of the calculated and experimental field emission scanning electron microscopy (FE-SEM) images. First-principle calculations at a density functional theory level were performed to obtain the values of surface energies and relative stability of the (120), (001), (011), (201), and (100) surfaces by employing the Wulff construction. The results of photoluminescence clearly show the specific emissions of Tb3+ and Eu3+. The values of the chromaticity coordinates were influenced by the increase in the treatment temperature, showing emission in the yellowish orange, green and white regions.

MEMBROS DA BANCA:
Presidente - 1802888 - FABIANA VILLELA DA MOTTA
Interno - 1883170 - MAURICIO ROBERTO BOMIO DELMONTE
Externo ao Programa - 2941160 - JOSE HERIBERTO OLIVEIRA DO NASCIMENTO
Externo à Instituição - MAXYMME MENDES DE MELO - IFRN
Externo à Instituição - VINÍCIUS DANTAS DE ARAÚJO - UFRPE