Origin of Magnetism and trend in $T_{c}$ in Cr-based double perovskites:   Interplay of two driving mechanisms
  Employing first principles density functional calculations, together with solution of the low-energy, model Hamiltonian constructed in a first principles manner, we explored the origin of magnetism and $T_c$ trend in Cr-based double perovskite series, Sr$_2$CrB$'$O$_6$ (B$'$=W/Re/Os). Our study shows that the apparently puzzling $T_c$ trend in Sr$_2$CrB$'$O$_6$ (B$'$=W/Re/Os) series can be understood in terms of the interplay of the hybridization driven mechanism and the super-exchange mechanism. 
Hena Das, Prabuddha Sanyal, T. Saha-Dasgupta, D.D. Sarma
cond-mat.mtrl-sci