Dresden 2017 – wissenschaftliches Programm
MA 15.12: Vortrag
Montag, 20. März 2017, 18:00–18:15, HSZ 403
First principles study of orbital order in Mn doped FeV2O4 — Dibyendu Dey1, •Tulika Maitra2, and Arghya Taraphder1 — 1Department of Physics, Indian Institute of Technology, Kharagpur 721302, India — 2Department of Physics, Indian Institute of Technology, Roorkee 247667, India
The long range orbital order in vanadium spinel oxides has been thoroughly debated by condensed matter physicists in recent years. MnV2O4 and FeV2O4 are two such compounds where the debate is centered around whether there are complex or real orbitals involved in the ordering process. In this context, we have investigated the long range orbital order in Mn doped FeV2O4 as a function of Mn doping (x). We have employed first-principles density functional theory (DFT) including Coulomb correlation (GGA+U) and spin-orbit interaction (GGA+U+SO) as well as the wannierization of our DFT derived vanadium d-bands for our analysis of the orbital order in these systems. We observe that for x≤0.6, the orbital order at V sites consists of a linear superposition of dxz and dyz orbitals of the type dxz±dyz whereas for x > 0.6, A-type ordering is observed. The effect of spin-orbit interaction on orbital ordering is found to be not significant in the entire range of doping studied indicating the absence of complex orbitals in the ordering. We also analyze the orbital ordering from the Raman spectrum calculated using ab-initio phonon within the DFT framework and compare the same with the experimental observations.
Reference:  Dibyendu Dey, T. Maitra, and A. Taraphder; Phys. Rev. B 93, 195133 (2016)