Magnetic component of mixing enthalpy for BCC Fe-Cr alloys: ab initio based model

The standard magnetic model in the current CALPHAD modelling is based on the Inden–Hillert–Jarl model and can be used to ferromagnetic and antiferromagnetic alloys. In this work, we demonstrate that this model can also be applied to alloys with more complicated forms of magnetism. The concept of 'effective magnetic moment' has been introduced as a measure of the maximum magnetic entropy. To calculate this quantity, it is necessary to know the local magnetic moments on the atoms of the components. A case study on the Fe –Cr system has been performed by Density Functional Theory (DFT) formalism at 0 K. It is shown that the CALPHAD modelling using the concept of effective magnetic moment leads to good agreement with the data of ab-initio modeling of the magnetic contribution to the mixing energy of Fe-Cr alloys. (paper)