Mechanism responsible for initiating room temperature ferromagnetism and spin polarized current in diluted magnetic oxides

TL;DR

This paper uncovers how electronic and band structure modifications in diluted magnetic oxides can induce room temperature ferromagnetism and spin-polarized currents, advancing spintronics applications.

Contribution

It demonstrates that tuning electronic structures and band structures can initiate DMO properties, revealing the origin of spintronic characteristics in these materials.

Findings

Doped Co ions and oxygen vacancies contribute magnetic moments in semiconducting state.

Magnetic coupling is mediated by localized carriers via spin-polarized hopping transport.

Electronic structure modifications can induce high TC ferromagnetism and spin polarization.

Abstract

The main obstacles in realizing diluted magnetic oxide (DMO) in spintronics are the unknown electronic structures associated with its high TC ferromagnetism and spin polarized current and how to manipulate desired electronic structures by fabrication techniques. We demonstrate that fine-tuned electronic structures and band structures can be modified to initiate DMO properties. Interestingly, in the semiconducting state, the doped Co ions and oxygen vacancies contribute non-negligible magnetic moments; and the magnetic coupling between these moments is mediated by the localized carriers via highly spin polarized hopping transport. These results unravel the myth of the origin of spintronic characteristics with desirable electronic states; thereby reopening the door for future applications.