Materials Science Research Lecture

***Refreshments at 3:45pm in Noyes lobby

Abstract:
Anharmonic vibrational dynamics play a crucial role in determining the physical properties of crystalline materials, impacting thermal conductivity, phase transitions, ion transport, and optoelectronic behavior.

In this talk, I will present an intuitive framework for understanding anharmonicity and demonstrate how Raman spectroscopy, combined with coupled mode models, provides a powerful tool for probing these dynamics. I will illustrate this approach through three case studies: (1) the temperature evolution of hydrogen-bond vibrations in glycine crystals, (2) soft modes and phase transitions in bismuth vanadate, and (3) electron-phonon coupling in heavily doped silicon.

A key takeaway from this analysis is that modeling with coupled mode pairs, rather than a single damped oscillator, effectively captures material behavior, bridging equilibrium and non-equilibrium dynamics and providing deeper insight into complex vibrational interactions in crystals.