Charge ordering in the metal–insulator transition of V-doped CrO2 in the rutile structure
- 1 Downloads
Electronic, magnetic, and structural properties of pure and V-doped CrO2 were extensively investigated utilizing density functional theory. Usually, pure CrO2 is a half-metallic ferromagnet with conductive spin majority species and insulating spin minority species. This system remains in its half-metallic ferromagnetic phase even at 50% V-substitution for Cr within the crystal. The V-substituted compound Cr0.5V0.5O2 encounters metal–insulator transition upon the application of on-site Coulomb repulsion U = 7 eV preserving its ferromagnetism in the insulating phase. It is revealed in this study that Cr3+-V5+ charge ordering accompanied by the transfer of the single V-3d electron to the Cr-3dt2g orbitals triggers metal–insulator transition in Cr0.5V0.5O2. The ferromagnetism of Cr0.5V0.5O2 in the insulating phase arises predominantly due to strong Hund’s coupling between the occupied electrons in the Cr-t2g states. Besides this, the ferromagnetic Curie temperature (Tc) decreases significantly due to V-substitution. Interestingly, a structural distortion is observed due to tilting of CrO6 or VO6 octahedra across the metal–insulator transition of Cr0.5V0.5O2.
KeywordsRutile CrO2 Spintronics devices Magnetoresistive random access memory (MRAM) First-principles calculations Local density approximations (LDA)
- 5.Lu J, West KG, Wolf SA (2010) Thin film metal-oxides. Ed. Ramanathan S Springer (US): p 95Google Scholar
- 15.Singh A, Jansen C, Lahabi K, Aarts J (2016) High-quality CrO2 nanowires for dissipation-less spintronics. Phys Rev X 6:041012Google Scholar
- 23.Harry G (1964) Electrons and chemical bonding. Benjamin, New YorkGoogle Scholar