Banca de QUALIFICAÇÃO: GUILHERME SIMOES DE CARLI

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : GUILHERME SIMOES DE CARLI
DATE: 22/09/2026
TIME: 14:00
LOCAL: Auditório PD
TITLE:

Computational Modeling of the Physical and Chemical Properties of Europium-Doped Sulfate Compounds

KEY WORDS:

Alkaline-earth sulfates; doping; europium; luminescence.

PAGES: 125
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Cerâmicos
SUMMARY:

Sulfates ASO4 (A = Mg, Ca, Sr, Ba) have been widely used in ionizing radiation dosime try, radiative cooling, radiation conversion, and photocatalysis applications. These materials are insulating host matrices that, when doped with lanthanide ions, exhibit distinctive thermo luminescence, optically stimulated luminescence, and photoluminescence properties. From a theoretical perspective, classical modeling has proven to be an effective approach for determi ning several properties of these materials, particularly the charge-compensating mechanisms associated with doping. In addition to energetic aspects, the local symmetry of the lanthanide ion, which directly influences the spectral characteristics of luminescence emission, can also be determined. Nevertheless, a comprehensive understanding of the charge-compensating mecha nisms of lanthanide ions incorporated into sulfate matrices is still lacking, particularly in the case of europium. Therefore, a computational study was conducted on sulfate materials ASO4 (A = Mg, Ca, Sr, Ba) doped with Eu2+ and Eu3+. A new set of potential parameters based on the Born model was fitted and validated by reproducing the structural, elastic, mechanical, and dielectric properties of these materials. Intrinsic and extrinsic defect calculations were per formed, showing a higher probability of forming cation Frenkel and pseudo-Schottky defects. For extrinsic defects, the most favorable configurations for europium incorporation into the lattice involved the substitution of Eu2+ and Eu3+ at cationic sites. Two charge-compensation mechanisms were proposed for extrinsic defects: compensation by interstitial oxygen and com pensation involving both cation and anion interstitials.

COMMITTEE MEMBERS:
Presidente - 2264069 - HEVESON LUIS LIMA DE MATOS
Interno - 1883366 - MURILO SODRE MARQUES
Interno - 1582257 - JORGE LUIS OLIVEIRA SANTOS