Magnetic thermodynamics of fcc Ni from first-principles partition function approach

Exploration of longstanding issues in magnetic materials, for example the nature of Curie/Neel temperature and the Schottky anomaly of heat capacity, appeals to reliable models at finite temperatures. Based on first-principles calculations and partition function approach with the microstates being the collinear magnetic configurations, the magnetic thermodynamics of fcc Ni, including the heat capacity and the pressure-dependent Curie temperature, is predicted well and compared with the results from experiments and mean-field approach. As demonstrated in fcc Ni, it is found that the magnetic thermodynamics containing anomalies stems from the magnetic configurational entropy caused by the competition of various magnetic states. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3524480]