Electronic density of states of body-centered-cubic Fe under phonon excitations, boron doping and amorphization

It has been shown that the intrinsic magnon damping in metallic ferromagnetic materials is proportional to the electronic density of states (EDOS) at Fermi level. This is theoretically described by the breathing Fermi surface model. Understanding how the EDOS at the Fermi level is affected by different factors has potential value for experimentalists to optimize low-damping magnetic materials for applications in spintronics and magnonics. To investigate this question, we consider a paradigmatic ferromagnetic material, the body-centered-cubic iron (Fe). We calculate the EDOS of Fe based on the density functional theory (DFT) using the Vienna Ab-Initio Simulation Package (VASP). Three different scenarios are considered: 1) Fe with thermal lattice disorder, 2) Fe doped by boron (B) and 3) Fe in an amorphous state. We have observed that, while the EDOS at Fermi level is not much affected by phonons up to the temperature of 500K, it is significantly reduced by B doping. Lowered EDOS at Fermi level can also be achieved in the amorphous Fe and FeB. 

Acknowledgements: this work was supported by the US Department of Energy, Office of Science, Materials Science and Engineering Division, under Contract No. DE-SC0022060. This work made use of the Illinois Campus Cluster, a computing resource that is operated by the Illinois Campus Cluster Program (ICCP) in conjunction with the National Center for Supercomputing Applications (NCSA) and which is supported by funds from the University of Illinois at Urbana-Champaign.