New Superconducting and Semiconducting Fe-B Compounds Predicted with an   Ab Initio Evolutionary Search
  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. 
A. N. Kolmogorov, S. Shah, E. R. Margine, A. F. Bialon, T.   Hammerschmidt, and R. Drautz
cond-mat.mtrl-sci