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Pulsed laser deposited films of Co doped anatase TiO2 are examined for Co substitutionality, ferromagnetism, transport, magnetotransport and optical properties. Our results show limited solubility (up to ~ 2 %) of Co in the as-grown films…

We revisit the most widely investigated and controversial oxide diluted magnetic semiconductor (DMS), Co:TiO2, with a new high temperature film growth, and show that the corresponding material is not only an intrinsic DMS ferromagnet, but…

In recent years there has been an intense search for room temperature ferromagnetism in doped dilute semiconductors, which have many potentially applications in spintronics and optoelectronics. We report here the unexpected observation of…

Pure rutile Co-doped TiO$_2$ films were fabricated successfully by the conventional pulsed laser deposition technique on silicon substrates from a ceramic target. Under the right fabrication conditions, Co concentration in the films could…

Materials Science · Physics 2009-11-10 Nguyen Hoa Hong , Joe Sakai , W. Prellier , Awatef Hassini

Transparent pure and Cu-doped (2.5, 5 and 10 at. %) anatase TiO2 thin films were grown by pulsed laser deposition technique on LaAlO3 substrates. The samples were structurally characterized by X-ray absorption spectroscopy and X-ray…

Thin films of Co-TiO2 are deposited on silicon and quartz substrates using Pulse Laser Deposition (PLD) process at various oxygen partial pressures ranging from 6.6 x 10-3 Pascals (Pa) to 53 Pa. Crystal structure, transport and magnetic…

Materials Science · Physics 2007-05-23 Bakhtyar Ali , Abdul K Rumaiz , S. Ismat Shah , Arif Ozbay , Edmund R Nowak

Anatase Ti0.96Co0.04O2 films were grown epitaxially on SrTiO3 (001) substrates by using plused laser deposition with in-situ reflection high-energy electron diffraction. The oxygen partial pressure, PO2, during the growth was systematically…

Materials Science · Physics 2009-11-07 D. H. Kim , J. S. Yang , K. W. Lee , S. D. Bu , T. W. Noh , S. -J. Oh , Y. -W. Kim , J. -S. Chung , H. Tanaka , H. Y. Lee , T. Kawai

Electric and magnetic properties of a high temperature ferromagnetic oxide semiconductor, cobalt-doped rutile TiO2, are summarized. The cobalt-doped rutile TiO2 epitaxial thin films with different electron densities and cobalt contents were…

Materials Science · Physics 2009-11-13 T Fukumura , H Toyosaki , K Ueno , M Nakano , M Kawasaki

Ferromagnetism is observed at and above room temperature in pulsed laser deposited epitaxial films of Co-doped Ti-based oxide perovskite (La1-xSrxTiO3-d). The system has the characteristics of an intrinsic diluted magnetic semiconductor…

TiO$_{2-\delta}$ films were deposited on (100) Lanthanum aluminates LaAlO$_{3}$ substrates at a very low oxygen chamber pressure $P\approx 0.3$ mtorr employing a pulsed laser ablation deposition technique. In previous work, it was…

Other Condensed Matter · Physics 2009-11-13 Soack Dae Yoon , Vincent G. Harris , Carmine Vittoria , Allan Widom

We have studied magnetism in anatase Ti$_{1-x}$Co$_x$O$_{2-\delta}$ ({\it x} = 0.05) thin films with various electron carrier densities, by soft x-ray magnetic circular dichroism (XMCD) measurements at the Co $L_{2,3}$ absorption edges. For…

Colloidal cobalt-doped TiO2 (anatase) nanocrystals were synthesized and studied by electronic absorption, magnetic circular dichroism, transmission electron microscopy, magnetic susceptibility, cobalt K-shell X-ray absorption spectroscopy,…

Materials Science · Physics 2007-05-23 J. Daniel Bryan , Steve M. Heald , Scott A. Chambers , Daniel R. Gamelin

Nano granular metallic iron (Fe) and titanium dioxide (TiO$_{2-\delta}$) were co-deposited on (100) lanthanum aluminate (LaAlO$_3$) substrates in a low oxygen chamber pressure using a pulsed laser ablation deposition (PLD) technique. The…

Materials Science · Physics 2009-11-13 S. D. Yoon , C. Vittoria , V. G. Harris , A. Widom , K. E. Miller , M. E. McHenry

Thin films of 5 % Co doped Cu2O were grown on single crystal (001) MgO substrates by pulsed laser deposition, without and with 0.5 % codoping with Al, V or Zn. Structural, electrical, and magnetic properties were studied. The films showed…

Condensed Matter · Physics 2009-11-10 S. N. Kale , S. B. Ogale , S. R. Shinde , M. Sahasrabuddhe , V. N. Kulkarni , R. L. Greene , T. Venkatesan

The Co-doped anatase TiO$_{2}$, a recently discovered room-temperature ferromagnetic insulator, has been studied by the first-principles calculations in the pseudo-potential plane-wave formalism within the local-spin-density approximation…

Materials Science · Physics 2007-05-23 Hongming Weng , Xiaoping Yang , Jinming Dong , H. Mizuseki , M. Kawasaki , Y. Kawazoe

It is shown that dilute niobium doping has significant effect on the ferromagnetism and microstructure of dilutely cobalt-doped anatase TiO2 films. Epitaxial films of anatase TiO2 with 3% Co, without and with 1% niobium doping were grown by…

Materials Science · Physics 2009-11-11 S. X. Zhang , S. B. Ogale , L. F. Fu , S. Dhar , D. C. Kundaliya , W. Ramadan , N. D. Browning , T. Venkatesan

Room-temperature ferromagnetism has been recently discovered in Co-doped TiO$_2$ rutile. Our $ab$ $initio$ density-functional theory investigations show that the substitutional Co ions incorporated into TiO$_2$ rutile tend to cluster and…

Materials Science · Physics 2007-05-23 W. T. Geng , K. S. Kim

We report on the magnetic properties of thoroughly characterized Zn1-xCoxO epitaxial thin films, with low Co concentration, x=0.003-0.005. Magnetic and EPR measurements, combined with crystal field theory, reveal that isolated Co2+ ions in…

Materials Science · Physics 2007-05-23 P. Sati , R. Hayn , R. Kuzian , S. Regnier , S. Schafer , A. Stepanov , C. Morhain , C. Deparis , M. Laugt , M. Goiran , Z. Golacki

Magneto-optical spectroscopy of a transparent ferromagnetic semiconductor, anatase TiO2 doped with Co, is carried out at room temperature. A large magneto-optical response with ferromagnetic field dependence is observed throughout from…

By pulsed-laser deposition epitaxial thin films of Sr_2FeMoO_6 have been pre- pared on (100) SrTiO_3 substrates. Already for a deposition temperature of 320 C epitaxial growth is achieved. Depending on deposition parameters the films show…

Materials Science · Physics 2009-10-31 W. Westerburg , D. Reisinger , G. Jakob
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