Top views of the structure models for iron silicides. (a) The 2 × 2 structure model. (b) The c (4 × 8) structure model proposed by Krause et al. [2,12]. A rhombic unit cell and a parallelogram unit cell are outlined in (a) and (b), respectively.
Zou et al. Nanoscale Research Letters 2013 8:510 doi:10.1186/1556-276X-8-510