Thermodynamics and Defects in Solids M1

This module is designed to provide basic knowledge of the thermodynamics of defects. Understanding the basic concepts of defects in stoichiometric and non-stoichiometric solids is essential for better understanding and designing materials for ionic and electronic conductivity, with particular relevance to energy materials. The lecture introduces and discusses the nature of point defects that disrupt the perfect geometry of ideal crystal structures:

• Introduction to point defects (missing or misplaced atoms, ions, or electrons)
• Discussion of Thermodynamic Concepts Related to Order-Disorder Phenomena in Solid Solutions
• Understanding Brouwer diagrams for oxides in order to highlight the role of the surrounding atmosphere on defect equilibrium at high temperatures.
• This study investigates the diffusion pathways and energies of ions and electrons—a major consequence of point defects—that give rise to electrical transport in ionic conductors.
• This paper describes experimental investigations into the measurement of ionic conductivity as a function of temperature. The method of impedance spectroscopy measurements is discussed.
• Presentation of the Kröger-Vink Notation for Defects
• Mott-Hubbard insulators

Hourly volumes*:

CM: 24

TD: 12

An understanding of the role of point defects in solids on transport properties and structural stability.

To apply the concept of the Brouwer diagram to control conductivity in oxides.

Electronic and Ionic Conductivity in Metallic Oxides

Understanding the Concepts of Ceramic Semiconductors

CC

- Ceramic (oxide) materials with metallic conductivity

- Defect chemistry (explaining the properties of semiconductors and ionic conductors)

- Crystal-field splitting of d-orbitals

- Strong electron correlation (Coulomb repulsion)

- Structural instabilities (Peierls distortion)

- Anderson localization (electron localization when the concentration of impurities or defects is high)

- Mott-Hubbard insulators

- Ceramic semiconductors

- point defects

- extended defects

- Presentation of the Kröger-Vink Notation for Defects

- Ionic conductors. Solid-oxide fuel cells. Batteries.

- Brouwer diagrams and defect equilibrium at high temperatures

- This study investigates the diffusion pathways and energies of ions and electrons in ionic conductors—a major consequence of point defects—which give rise to electrical transport.

- Experimental investigations of ionic conductivity as a function of temperature using impedance spectroscopy measurements

Administrative contact(s): Chemistry Master's Program Office master-chimie@umontpellier.fr