Please use this identifier to cite or link to this item:
|Title:||Cationic-vacancy-induced room-temperature ferromagnetism in transparent, conducting anatase Ti 1-xTa xO 2 (x ∼0.05) thin films||Authors:||Rusydi, A.
Roy Barman, A.
|Issue Date:||28-Oct-2012||Citation:||Rusydi, A., Dhar, S., Roy Barman, A., Ariando, Qi, D.-C., Motapothula, M., Yi, J.B., Santoso, I., Feng, Y.P., Yang, K., Dai, Y., Yakovlev, N.L., Ding, J., Wee, A.T.S., Neuber, G., Breese, M.B.H., Ruebhausen, M., Hilgenkamp, H., Venkatesan, T. (2012-10-28). Cationic-vacancy-induced room-temperature ferromagnetism in transparent, conducting anatase Ti 1-xTa xO 2 (x ∼0.05) thin films. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370 (1977) : 4927-4943. ScholarBank@NUS Repository. https://doi.org/10.1098/rsta.2012.0198||Abstract:||We report room-temperature ferromagnetism (FM) in highly conducting, transparent anatase Ti 1-xTaxO 2 (x ∼0.05) thin films grown by pulsed laser deposition on LaAlO 3 substrates. Rutherford backscattering spectrometry (RBS), X-ray diffraction, protoninduced X-ray emission, X-ray absorption spectroscopy (XAS) and time-of-flight secondary-ion mass spectrometry indicated negligible magnetic contaminants in the films. The presence of FM with concomitant large carrier densities was determined by a combination of superconducting quantum interference device magnetometry, electrical transport measurements, soft X-ray magnetic circular dichroism (SXMCD), XAS and optical magnetic circular dichroism, and was supported by first-principles calculations. SXMCD and XAS measurements revealed a 90 per cent contribution to FM from the Ti ions, and a 10 per cent contribution from the O ions. RBS/channelling measurements show complete Ta substitution in the Ti sites, though carrier activation was only 50 per cent at 5 per cent Ta concentration, implying compensation by cationic defects. The role of the Ti vacancy (V Ti) and Ti 3+ was studied via XAS and X-ray photoemission spectroscopy, respectively. It was found that, in films with strong FM, the V Ti signal was strong while the Ti 3+ signal was absent. We propose (in the absence of any obvious exchange mechanisms) that the localized magnetic moments, V Ti sites, are ferromagnetically ordered by itinerant carriers. Cationic-defect-induced magnetism is an alternative route to FM in wide-band-gap semiconducting oxides without any magnetic elements. © 2012 The Royal Society.||Source Title:||Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences||URI:||http://scholarbank.nus.edu.sg/handle/10635/84430||ISSN:||1364503X||DOI:||10.1098/rsta.2012.0198|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Aug 16, 2019
WEB OF SCIENCETM
checked on Aug 9, 2019
checked on Aug 17, 2019
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.