Electronic structure and superconductivity of rare-earth pnictides

In this work, we have studied the electronic structure of iron-based superconductors LnFePO (Ln = =La, Pr, Nd, Sm and Gd) and their non-superconducting analogue CeFePO using a first principles method through the band structure calculations. Fe 3d electronic bands are at the origin of the fascinating electronic properties of these materials. The height of the pnictogen h_Pn and the bond angle Fe-Pn-Fe have been calculated and discussed. We have shown that the behavior of Fe-d_z² and Fe-d_xy orbitals under the effect of the rare earth element variation is responsible for the increase of the critical temperature in these systems.