Orbital-Ordering Induces Structural Phase Transition and the Resistivity Anomaly in Iron Pnictides

Weicheng Lv, Jiansheng Wu, Philip Phillips

We attribute the structural phase transition (SPT) in the parent compounds of the iron pnictides to orbital ordering. Due to the anisotropy of the $d_{xz}$ and $d_{yz}$ orbitals in…