Defect-band mediated ferromagnetism in Gd-doped ZnO thin films

Gd-doped ZnO thin films prepared by pulsed laser deposition with Gd concentrations varying from 0.02–0.45 atomic percent (at. %) showed deposition oxygen pressure controlled ferromagnetism. Thin films prepared with Gd dopant levels (<Gd 0.112 at. %) at low oxygen deposition pressure (<25 mTorr...

Full description

Saved in:
Bibliographic Details
Main Authors: Venkatesh, S., Franklin, J. B., Ryan, M. P., Lee, J.-S., Ohldag, Hendrik, McLachlan, M. A., Alford, N. M., Roqan, I. S.
Other Authors: Energy Research Institute @ NTU (ERI@N)
Format: Article
Language:English
Published: 2015
Subjects:
Online Access:https://hdl.handle.net/10356/106886
http://hdl.handle.net/10220/25222
Tags: Add Tag
No Tags, Be the first to tag this record!
Institution: Nanyang Technological University
Language: English
Description
Summary:Gd-doped ZnO thin films prepared by pulsed laser deposition with Gd concentrations varying from 0.02–0.45 atomic percent (at. %) showed deposition oxygen pressure controlled ferromagnetism. Thin films prepared with Gd dopant levels (<Gd 0.112 at. %) at low oxygen deposition pressure (<25 mTorr) were ferromagnetic at room temperature. Negative magnetoresistance, electric transport properties showed that the ferromagnetic exchange is mediated by a spin-split defect band formed due to oxygen deficiency related defect complexes. Mott's theory of variable range of hopping conduction confirms the formation of the impurity/defect band near the Fermi level.