Anomalous magnetic behaviors of double perovskite R2CrFeO6 (R=rare earth elements) predicted by first-principles calculations

•Structural and magnetic behaviors of double perovskite R2CrFeO6 were investigated by first-principles calculations.•For all the R2CrFeO6, ferrimagnetic in monoclinic P21/n phase is the ground state.•A larger R radius can reduce the energy differences between P21/n and R-3 phases.•TN decreases linearly as the R radius increases, different from R2NiMnO6 and R2CoMnO6.•Besides generating tilting angles, rare earth ions can also affect the exchange coupling of R2CrFeO6 in other ways.