Chapter 2: Free Energy of Pure Substances

This chapter describes the basics of energy and entropy and “free energy.” Fundamentals of internal energy U, the enthalpy H, entropy S, free energies G, and F of a substance are presented. The chapter also presents the thermal vibration model to promote a better understanding of the U, S, and F of the crystal. It covers basic concepts of thermodynamics of magnetic transition and discusses the role and the meaning of magnetic transition in iron and steel. The chapter concludes with a general discussion on an amorphous phase from a thermodynamic viewpoint.