Thermodynamic fluctuation among many electronic states in systems with 'itinerant-electron' magnetism is addressed with a first-principles formulation of the Helmholtz energy. The Ce γ-α phase transition is used as an illustrative case. The kBln(2J+1) form for the magnetic entropy that is commonly found in the literature is replaced with an expression that is derived from configurational fluctuations among nonmagnetic, ferromagnetic, and antiferromagnetic electronic states. Predicted first-and second-order magnetic phase transitions are in close accord with experiment. The mixture of states leads to a Schottky anomaly in the Ce specific heat.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics