Analytic Model of the Schottky Anomaly and Phase Transition

The Schottky anomaly is a peak in the specific heat at low temperatures without divergence, in contrast to a phase transition which is characterized by a singularity of a physical quantity. A model with the analytic form of a density function, where both the phase transition and the Schottky anomaly appear depending on the limit of the model parameters, is presented. The model allows a unified analytic treatment of the phase transition and the Schottky anomaly