Orbital ordering and magnetic structures in $\LMFO$ and $\LWFO$ double   perovskites
  We analyzed the possible magnetic and orbital orderings of double perovskites, using a simple extension of the double exchange model well suited for these compounds. Orbital ordering is favored by the on site repulsion at the Fe ions. We obtain a rich phase diagram, including ferri- and antiferromagnetic phases, which can, in turn, be metallic or insulating, depending on the existence of orbital order. 
A. Taraphder and F. Guinea