Experimental and theoretical studies of hydroxyl-induced magnetism in TiO nanoclusters

Xiao Hui Wei, Rulong Zhou, B. Balamurugan, Ralph Skomski, Xiao Cheng Zeng, D. J. Sellmyer

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

A main challenge in understanding the defect ferromagnetism in dilute magnetic oxides is the direct experimental verification of the presence of a particular kind of defect and distinguishing its magnetic contributions from other defects. The magnetic effect of hydroxyls on TiO nanoclusters has been studied by measuring the evolution of the magnetic moment as a function of moisture exposure time, which increases the hydroxyl concentration. Our combined experiment and density-functional theory (DFT) calculations show that as dissociative water adsorption transforms oxygen vacancies into hydroxyls, the magnetic moment shows a significant increase. DFT calculations show that the magnetic moment created by hydroxyls arises from 3d orbitals of neighboring Ti sites predominantly from the top and second monolayers. The two nonequivalent hydroxyls contribute differently to the magnetic moment, which decreases as the separation of hydroxyls increases. This work illustrates the essential interplay among defect structure, local structural relaxation, charge redistribution, and magnetism. The microscopic differentiation and clarification of the specific roles of each kind of intrinsic defect is critical for the future applications of dilute magnetic oxides in spintronic or other multifunctional materials.

Original languageEnglish (US)
Pages (from-to)7704-7711
Number of pages8
JournalNanoscale
Volume4
Issue number24
DOIs
StatePublished - Jan 1 2012

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Nanoclusters
Magnetism
Magnetic moments
Hydroxyl Radical
Defects
Density functional theory
Magnetoelectronics
Oxides
Structural relaxation
Defect structures
Ferromagnetism
Oxygen vacancies
Monolayers
Moisture
Adsorption
Water
Experiments

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Experimental and theoretical studies of hydroxyl-induced magnetism in TiO nanoclusters. / Wei, Xiao Hui; Zhou, Rulong; Balamurugan, B.; Skomski, Ralph; Zeng, Xiao Cheng; Sellmyer, D. J.

In: Nanoscale, Vol. 4, No. 24, 01.01.2012, p. 7704-7711.

Research output: Contribution to journalArticle

Wei, Xiao Hui ; Zhou, Rulong ; Balamurugan, B. ; Skomski, Ralph ; Zeng, Xiao Cheng ; Sellmyer, D. J. / Experimental and theoretical studies of hydroxyl-induced magnetism in TiO nanoclusters. In: Nanoscale. 2012 ; Vol. 4, No. 24. pp. 7704-7711.
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