First-principles study of orbital ordering in cubic fluoride KCrF₃

Comprehensive first-principles calculations are performed to provide insight into the intriguing physical properties of the ternary cubic fluoride KCrF₃. The electronic structures exhibit a prominent dependence on the effective local Coulomb interaction parameter U_eff. The ground state of the cubic phase is a ferromagnetic (FM) half-metal with U_eff equal to 0, 2, and 4 eV, whereas the insulating A-type antiferromagnetic (A-AFM) state with concomitant homogeneous orbital ordering is more robust than the FM state for U_eff exceeding 4 eV. We propose that the origin of the orbital ordering is purely electronic when the cooperative Jahn–Teller distortions are absent in cubic KCrF₃.