New candidate ground states at 1:4, 1:2, and 1:1 compositions are identified in the well-known Fe-B system via a combination of ab initio high-throughput and evolutionary searches. We show that the proposed oP12-FeB2 stabilizes by a break up of 2D boron layers into 1D chains while oP10-FeB4 stabilizes by a distortion of a 3D boron network. The uniqueness of these configurations gives rise to a set of remarkable properties: oP12-FeB2 is expected to be the first semiconducting metal diboride and oP10-FeB4 is shown to have the potential for phonon-mediated superconductivity with a Tc of 15-20 K.
@article{arxiv.1104.2135,
title = {New Superconducting and Semiconducting Fe-B Compounds Predicted with an Ab Initio Evolutionary Search},
author = {A. N. Kolmogorov and S. Shah and E. R. Margine and A. F. Bialon and T. Hammerschmidt and R. Drautz},
journal= {arXiv preprint arXiv:1104.2135},
year = {2011}
}