Electronic Structure and 3d-4f Exchange Interactions in Zircon-type RCrO4 Oxides (R=Dy, Ho and Gd)

Using first principles density functional theory (DFT) calculations within GGA and GGA+U approximations we studied both ferromagnetic (FM) and antiferromagnetic (AFM) phases of zircon type RCrO4 (R=Dy, Ho, Gd) oxides. We estimated and compared the 3d-4f exchange interaction strengths J between the nearest neighbor R3+ and Cr5+ ions for R=Dy, Gd. Our results predict that DyCrO4, GdCrO4 and HoCrO4 have ferromagnetic ground state which is consistent with experimental observations.