Orbital order and electron itinerancy in CoV$_{2}$O$_{4}$ and Mn$ _{0.5} $Co$ _{0.5} $V$_{2}$O$_{4}$ from first principles

Jyoti Krishna; T. Maitra

doi:10.1088/1361-648X/ab7e57

paper

Orbital order and electron itinerancy in CoV $_{2}$ O $_{4}$ and Mn $_{0.5}$ Co $_{0.5}$ V $_{2}$ O $_{4}$ from first principles

arXiv:1912.07051 · doi:10.1088/1361-648X/ab7e57

Abstract

In view of the recent experimental predictions of a weak structural transition in CoV $_{2}$ O $_{4}$ we explore the possible orbital order states in its low temperature tetragonal phases from first principles density functional theory calculations. We observe that the tetragonal phase with I4 $_{1} / am d$ symmetry is associated with an orbital order involving complex orbitals with a reasonably large orbital moment at Vanadium sites while in the phase with I4 $_{1} / a$ symmetry, the real orbitals with quenched orbital moment constitute the orbital order. Further, to study the competition between orbital order and electron itinerancy we considered Mn $_{0.5}$ Co $_{0.5}$ V $_{2}$ O $_{4}$ as one of the parent compounds, CoV $_{2}$ O $_{4}$ , lies near itinerant limit while the other, MnV $_{2}$ O $_{4}$ , lies deep inside the orbitally ordered insulating regime. Orbital order and electron transport have been investigated using first principles density functional theory and Boltzmann transport theory in CoV $_{2}$ O $_{4}$ , MnV $_{2}$ O $_{4}$ and Mn $_{0.5}$ Co $_{0.5}$ V $_{2}$ O $_{4}$ . Our results show that as we go from MnV $_{2}$ O $_{4}$ to CoV $_{2}$ O $_{4}$ there is enhancement in the electron's itinerancy while the nature of orbital order remains unchanged.

8 pages, 6 figures

Orbital order and electron itinerancy in CoV2​O4​ and Mn0.5​Co0.5​V2​O4​ from first principles

Abstract

References in corpus (8)

Orbital order and electron itinerancy in CoV $_{2}$ O $_{4}$ and Mn $_{0.5}$ Co $_{0.5}$ V $_{2}$ O $_{4}$ from first principles