Li and Fe codoped NiO thin films (LixNi0.98−xFe0.02O, x=0–0.05) were obtained by a sol-gel spin-coating method on silicon substrates. Phase composition and microstructure analysis indicated that the film samples contained 20–30nm sized NiO particles. With increasing Li-doping concentration, the current density of the films increased due to the increase of hole carriers. Magnetization measurements revealed that all the thin films showed room-temperature ferromagnetic properties and could be enhanced by Li doping, which should be due to the fact that hole doping makes ferromagnetic coupling interactions between the hole carriers and localized Fe 3d spins more efficient.

By means of photoemission and x-ray absorption spectroscopy, we have studied the electronic structure of (Ni,Zn,Fe,Ti)3O4 thin films, which exhibits a cluster glass behavior with a spin-freezing temperature Tf of ∼230K and photoinduced magnetization (PIM) below Tf. The Ni and Zn ions were found to be in the divalent states. Most of the Fe and Ti ions in the thin films were trivalent (Fe3+) and tetravalent (Ti4+), respectively. While Ti doping did not affect the valence states of the Ni and Zn ions, a small amount of Fe2+ ions increased with Ti concentration, consistent with the proposed charge-transfer mechanism of PIM.

We have performed an in situ depth profile study of Mn-doped GaN prepared by a low temperature thermal diffusion method using photoemission and x-ray absorption spectroscopy. It was revealed from the core-level photoemission measurements that Mn ions are diffused into a deep ͑ϳ70 Å͒ region of the GaN substrates and that the line shapes of Mn 3d partial density of states obtained by resonant photoemission measurements were close to that of Ga 1−x Mn x N thin films grown by molecular-beam epitaxy. From x-ray absorption spectroscopy and x-ray magnetic circular dichroism measurements at the Mn L edge, it was revealed that the doped Mn ions were in the divalent Mn 2+ state and primarily paramagnetic. In magnetization measurements, weak hysteresis was detected in samples prepared using p-type GaN substrates while samples using n-type GaN substrates showed only paramagnetism.

A study of the growth of Lu 2 O 3 on Si(001) by synchrotron radiation photoemission and transmission electron microscopy Surface electronic structure in transition-metal (Cr and Mn) doped GaAs (001) studied by in situ photoemission spectroscopy Appl.We have performed a depth profile study of thermally diffused Mn/GaAs ͑001͒ interfaces using photoemission spectroscopy combined with Ar + -ion sputtering. We found that Mn ion was thermally diffused into the deep region of the GaAs substrate and completely reacted with GaAs. In the deep region, the Mn 2p core-level and Mn 3d valence-band spectra of the Mn/GaAs ͑001͒ sample heated to 600°C were similar to those of Ga 1−x Mn x As, zinc-blend-type MnAs dots, and/or interstitial Mn in tetrahedrally coordinated by As atoms, suggesting that the Mn atoms do not form any metallic compounds but are tetrahedrally coordinated by ligand atoms, and Mn 3d states are hybridized with ligand orbitals lized but were hybridized with the electronic states of the host GaAs. Ferromagnetism was observed in the dilute Mn phase.