Combined effect of strain and screw dislocation on the ferromagnetic behavior of ZnO nanowires

Owing to its excellent structural flexibility, a noteworthy strain adaptability was discovered from the screw dislocation located in zinc oxide (ZnO) nanowires (NWs). Based on density functional theory (DFT), the electronic structure and magnetic coupling mechanism of Zn vacancies (VZn) in this dislocation while sustaining inhomogeneous strain patterns were explored. The electronic structure analysis revealed that a double screw characteristic could be observed from the center of the dislocation, where O atoms were under 3-fold coordination. This was beneficial to the capture of numerous V-Zn. Meanwhile, the most stable configuration was obtained under a-2% strain, which enhanced the stability and interaction of V-Zn, allowing the couplings of V-Zn to form steady V-Zn pairs. A stable ferromagnetic (FM) state then originated from the pi-pi spin couplings of surrounding O-2p orbits. It was deduced that the long-range FM ordering could be regulated by the combined effect of strain and screw dislocation.

Automated summary

The electronic structure and magnetic coupling mechanism of Zn vacancies in screw dislocations in zinc oxide nanowires were investigated using density functional theory. It was found that under specific strains, stable V-Zn pairs could be formed to achieve long-range ferromagnetic ordering.