Spacer-layer-tunable ferromagnetic half-metal-ferromagnetic insulator transition in SrVO3/SrTiO3 superlattice

In this work, the first-principle calculations based on density functional theory (DFT) are employed to investigate the electronic and magnetic properties of SrVO3/SrTiO3 (111) superlattices. The studies show that the transition from ferromagnetic half-metal to ferromagnetic insulator can be achieved by adjusting the thickness of the spacer-layer SrTiO3. The interlayer coupling between the SrVO3 sublayers can occur across two unit-cell (uc) distance of SrTiO3, and the superlattice is ferromagnetic half-metal. When the SrTiO3 sublayers are 3uc, a small band gap (about 0.28 eV) appears in the superlattice. When the SrTiO3 sublayers are more than 3uc, the superlattice has a large band gap and exhibits ferromagnetic insulating state. Further studies show that the Ti-V mixed defects play an important role in realizing the transition of metal-insulator. Compared with the ideal interface, the Ti-V mixed interface can inhibit the interlayer coupling and induce the transition of ferromagnetic half-metal to ferromagnetic insulator. These results provide a theoretical basis for the transition of ferromagnetic half-metal to ferromagnetic insulator by adjusting the number of SrTiO3 layers in SrVO3/SrTiO3 (111) superlattices.

Automated summary

The transition from ferromagnetic half-metal to ferromagnetic insulator in SrVO3/SrTiO3 superlattices can be achieved by adjusting the number of SrTiO3 layers. Ti-V mixed defects play a crucial role in this metal-insulator transition.