Systematic changes of the electronic structure of the diluted ferromagnetic oxide Li-doped Ni${}_{1-x}$Fe${}_x$O with hole doping

Abstract

The electronic structure of Li-doped Ni${}_{1-x}$Fe${}_x$O has been investigated using photoemission spectroscopy (PES) and x-ray absorption spectroscopy (XAS). The Ni $2p$ core-level PES and XAS spectra were not changed by Li doping. In contrast, the Fe${}^{3+}$ intensity increased with Li doping relative to the Fe${}^{2+}$ intensity. However, the increase of Fe${}^{3+}$ is only $\sim 5$ of the doped Li content, suggesting that most of the doped holes enter the O $2p$ and/or the charge-transferred configuration Ni $3d^8\underline{L}$. The Fe 3d partial density of states and the host valence-band emission near valence-band maximum increased with Li content, consistent with the increase of electrical conductivity. Based on these findings, percolation of bound magnetic polarons is proposed as an origin of the ferromagnetic behavior.

5 pages, 3 figures

References in corpus (5)

• Theory of ferromagnetic (III,Mn)V semiconductors
• Polaron percolation in diluted magnetic semiconductors
• High Temperature Ferromagnetism in GaAs-based Heterostructures with Mn Delta Doping
• Co-doped (La,Sr)TiO3-d: a high-Curie temperature diluted magnetic system with large spin-polarization
• Electronic structure of In${}_{1-x}$Mn${}_x$As studied by photoemission spectroscopy: Comparison with Ga${}_{1-x}$Mn${}_x$As

Cited by in corpus (1)

• Effect of co-doping of donor and acceptor impurities in the ferromagnetic semiconductor Zn1-xCrxTe studied by soft x-ray magnetic circular dichroism