The electronic structures of fcc Ce are calculated for large supercells with varying disorder by use of density-functional theory. Thermal disorder induces fluctuations of the amplitude of the magnetic moments and an increase in the average moments in the high-volume phase. The ferromagnetic solutions move towards a lower volume than in calculations for the perfectly ordered lattice. Therefore, disorder contributes via entropy to the stabilization of the $\gamma$ phase at high $T$, and it is important for an understanding of the $\alpha \text{−}\gamma$ transition. Core level spectroscopy would be a means to detect disorder through the spread of Madelung shifts and local exchange splittings.

• Received 27 March 2014
• Revised 15 May 2014

DOI:https://doi.org/10.1103/PhysRevB.89.184426