Thèse

Lundi 29 Juin 2026 à 10h00.

Solidification by micro-pulling down (μ-PD) of Al2O3-YAG and Al2O3-YAG-ZrO2 eutectic ceramics doped (Ce, Pr, Sm): microstructure-optical property relationships for LED and jewelry applications

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Directeur de thèse / thesis director :
K. Lebbou
Y. Guyot

Membres du jury / jury members :
Mariane Cochez Professor, Université Loraine, Reviewer
Rémy Boulesteix Doctor, Université Limoges, Reviewer
Alexandra Pena Doctor, Institut Néel, CNRS, Grenoble, Examiner
San Miguel Fuster Alfonso,Professor, ILM, UCB Lyon1, Examiner
Yannick Guyot Doctor, ILM, UCB Lyon1,Co-Supervisor
Kheirreddine Lebbou CNRS Research Director, ILM, UCB Lyon1, Supervisor

Résumé / Abstract :
This thesis focuses on the development and study of Al₂O₃–YAG and Al₂O₃–YAG–ZrO₂ eutectic ceramics, materials with remarkable thermal, mechanical, and optical properties. Doping with rare-earth ions (Ce³⁺, Pr³⁺, Sm³⁺) was used to modulate the luminescent properties, with particular interest for LED and decorative applications. The materials were synthesized using the micro-pulling down (µ-PD) technique, allowing precise control of the microstructure. The influence of growth parameters on the eutectic organization was investigated. An approach combining experimentation and modeling enabled the analysis of crystallization kinetics and associated thermal phenomena. The results show that cerium doping and co-doping (Ce/Pr, Ce/Sm) affect the microstructure and optical properties.

This work contributes to a better understanding of the relationships between process, microstructure and properties, and opens up perspectives for the development of innovative functional materials.

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