English

Is N-doped SrO magnetic? A first-principles view

Materials Science 2015-06-03 v1

Abstract

N-doped SrO seems to be one of the model systems for d^0 magnetism, in which magnetism (or ideally, ferromagnetism) was ascribed to the localized N 2p spins mediated by delocalized O 2p holes. Here we offer a different view, using density functional calculations. We find that N-doped SrO with solely substitutional N impurities as widely assumed in the literature is unstable, and instead that a pairing state of substitutional and interstitial N impurities is significantly more stable and has a much lower formation energy than the former by 6.7 eV. The stable (N_{sub}-N_{int})^{2-} dimers behave like a charged (N_2)^{2-} molecule and have each a molecular spin=1. However, their spin-polarized molecular levels lie well inside the wide band gap of SrO and thus the exchange interaction is negligibly weak. As a consequence, N-doped SrO could not be ferromagnetic but paramagnetic.

Keywords

Cite

@article{arxiv.1201.2213,
  title  = {Is N-doped SrO magnetic? A first-principles view},
  author = {Hua Wu},
  journal= {arXiv preprint arXiv:1201.2213},
  year   = {2015}
}

Comments

7 pages, 2 figures, Appl. Phys. Lett., in press

R2 v1 2026-06-21T20:02:59.306Z