Phase Transitions: Understanding Thermodynamic Stability

This lecture covers the fundamental concepts of phase transitions in thermodynamics, focusing on the stability of different phases. The instructor begins by introducing the main phases of matter: solid, liquid, and gas, along with other phases such as plasma and superconductors. Various experiments are presented to illustrate these concepts, including the creation of plasma through ionization and the transition of carbon dioxide from gas to solid. The lecture emphasizes the criteria for stability in thermodynamic systems, explaining how unstable phases transition to stable ones. The instructor discusses the concavity of entropy and the convexity of internal energy, detailing the conditions that lead to phase transitions. The relationship between temperature, pressure, and phase stability is also explored, alongside the implications of these transitions in real-world applications. The lecture concludes with a discussion on the stability of thermodynamic potentials and the significance of understanding these principles in the context of material science and engineering.