Dr Wolfgang Wisniewski

From

Friedrich Schiller University Jena - DE

In residence at

Extreme Conditions and Materials: High Temperature and Irradiation (CEMHTI) / CNRS - FR

Host scientist

Dr Mathieu Allix

PROJECT

Mechanisms of glass crystallization analyzed by electron backscatter diffraction (EBSD)

My goal in the context of the Le Studium fellowship is to improve knowledge in the field of glass crystallization mechanisms and develop innovative glass ceramics in collaboration with M. Allix at the
CEMHTI laboratory on the CNRS campus in Orléans. This project is based on applying electron backscatter diffraction (my field of expertise) to crystallized glasses provided by M. Allix. I will also establish the method in Orléans by transferring my capabilities to the host group.

Electron backscatter diffraction (EBSD) is performed in a scanning electron microscope (SEM) and can be used to analyze crystalline phases, i.e. it is useful when analyzing ceramics, glass ceramics, metals, geological samples and much more. EBSD can provide local crystal orientation information down to the nm-scale but also information concerning orientation preferences (textures) up to the cm scale.

I have applied EBSD to various materials with a focus on crystallized glasses and often expanded the knowledge concerning the respective materials as well as disproved incorrect views in various fields. I have e.g. used EBSD to prove the oriented nucleation in glasses, which stands in contrast to the random nucleation generally assumed in the field.

Collaborating with the group of M. Allix, which is focused on developing new optical materials via the crystallization of glasses, will enable me to access state of the art technology and perform fundamental research concerning the oriented nucleation in glasses. Simultaneously, the detailed information about crystal growth provided by EBSD will enable for formulate detailed growth models concerning the crystallization of the provided glasses which in turn can lead to innovative approaches towards developing and optimizing new glass-ceramics and ceramics.

The CNRS/University campus in Orléans will acquire a new SEM with an EBSD camera (to be delivered at the end of 2018). Hence this project will also permit E. Véron, the SEM expert in the team of M. Allix, to rapidly acquire experience using EBSD directly applicable to glass crystallization, thanks to a tight collaboration with me on this new equipment.