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Fe-doped ZnO nanocrystals are successfully synthesized and structurally characterized by using x-ray diffraction and transmission electron microscopy. Magnetization measurements on the same system reveal a ferromagnetic to paramagnetic…

Unexpected ferromagnetism has been observed in carbon doped ZnO films grown by pulsed laser deposition [Phys. Rev. Lett. 99, 127201 (2007)]. In this letter, we introduce carbon into ZnO films by ion implantation. Room temperature…

Wereport the results of a sequence of magnetisation and magneto-optical studies on laser ablated thin films of ZnCoAlO and ZnCoO that contain a small amount of metallic cobalt. The results are compared to those expected when all the…

Magnetic 3d-ions doped into wide-gap oxides show signatures of room temperature ferromagnetism, although their concentration is two orders of magnitude smaller than that in conventional magnets. The prototype of these exceptional materials…

Materials Science · Physics 2009-11-13 C. D. Pemmaraju , R. Hanafin , T. Archer , H. B. Braun , S. Sanvito

Recently theoretical works predict that some semiconductors (e.g. ZnO) doped with magnetic ions are diluted magnetic semiconductors (DMS). In DMS magnetic ions substitute cation sites of the host semiconductor and are coupled by free…

Materials Science · Physics 2009-07-22 Shengqiang Zhou , K. Potzger , Qingyu Xu , G. Talut , M. Lorenz , W. Skorupa , M. Helm , J. Fassbender , M. Grundmann , H. Schmidt

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

Magneto-optic studies of ZnO doped with transition metals Co, Mn, V and Ti indicate a significant magnetic circular dichroism (MCD) at the ZnO band edge at room temperature, together with an associated dispersive Faraday rotation. Similar…

Strongly Correlated Electrons · Physics 2009-11-11 JR Neal , AJ Behan , RM Ibrahim , H J Blythe , M Ziese , AM Fox , GA Gehring

The possibility that the apparent room temperature ferromagnetism, often measured in Co-doped ZnO, is due to uncompensated spins at the surface of wurtzite CoO nanoclusters is investigated by means of a combination of density functional…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Ruairi Hanafin , Thomas Archer , Stefano Sanvito

We recently reported the observation of room temperature ferromagnetism in mixtures of ZnO and Co3O4 despite the diamagnetic and antiferromagnetic character of these oxides respectively. Here we present a detailed study on the electronic…

Nowadays ferromagnetism is often found in potential diluted magnetic semiconductor systems. However, many authors argue that the observed ferromagnetism stems from ferromagnetic precipitates or spinodal decomposition rather than from…

We report on the synthesis of high-quality Co-doped ZnO thin films using the pulsed laser deposition technique on (0001)-Al$_2$O$_3$ substrates performed in an oxidizing atmosphere, using Zn and Co metallic targets. We firstly optimized the…

Materials Science · Physics 2009-11-10 W. Prellier , A. Fouchet , B. Mercey , Ch. Simon , B. Raveau

Highly oriented polycrystalline SSMO thin films deposited on single crystal substrates by ultrasonic nebulized spray pyrolysis have been studied. The film on LAO is under compressive strain while LSAT and STO are under tensile strain. The…

Strongly Correlated Electrons · Physics 2013-05-20 Manoj K. Srivastava , Sandeep Singh , P. K. Siwach , Amarjeet Kaur , V. P. S. Awana , K. K. Maurya , H. K. Singh

The magnetic properties of Zn$_{1-x}$Co$_x$O ($x=0.07$ and 0.10) thin films, which were homo-epitaxially grown on a ZnO(0001) substrates with varying relatively high oxygen pressure, have been investigated using x-ray magnetic circular…

We report on the synthesis of low doping Zn$_{1-x}$Co$_x$O ($0<x<0.1$) thin films on (0001)-Al$_2$O$_3$ substrates. The films were prepared in an oxidizing atmosphere, using the pulsed laser deposition technique starting from Zn and Co…

Materials Science · Physics 2009-11-10 A. Fouchet , W. Prellier , P. Padhan , Ch. Simon , B. Mercey , V. N. Kulkarni , T. Venkatesan

We report magnetism in carbon doped ZnO. Our first-principles calculations based on density functional theory predicted that carbon substitution for oxygen in ZnO results in a magnetic moment of 1.78 $\mu_B$ per carbon. The theoretical…

Materials Science · Physics 2013-05-29 H. Pan , J. B. Yi , J. Y. Lin , Y. P. Feng , J. Ding , L. H. Van , J. H. Yin

Sol-gel derived thin films of Zn0.95Mn0.05O have been implanted with Ar9+ ions with doses viz. 5x10e14 ions/cm2 (low), 1x10e15 ions/cm2 (intermediate) and 1x10e16 ions/cm2 (high). Structural, morphological, optical and magnetic properties…

We studied the ferroelectric and ferromagnetic properties of compressive strained and unstrained BiMnO3 thin films grown by rf-magnetron sputtering. BiMnO3 samples exhibit a 2D cube-on-cube growth mode and a pseudo-cubic struc-ture up to a…

Materials Science · Physics 2013-06-06 G. M. De Luca , D. Preziosi , F. Chiarella , R. Di Capua , S. Gariglio , S. Lettieri , M. Salluzzo

The realization of semiconductors that are ferromagnetic above room temperature will potentially lead to a new generation of spintronic devices with revolutionary electrical and optical properties. Transition temperatures in doped ZnO are…

Strongly Correlated Electrons · Physics 2009-11-11 XH Xu , AJ Behan , M Ziese , HJ Blythe , JR Neal , A Mokhtari , MR Ibrahim , AM Fox , GA Gehring

In the present study we report on properties of ZnCoO films grown at relatively low temperature by the Atomic Layer Deposition, using two reactive organic zinc precursors (dimethylzinc and diethylzinc). The use of these precursors allowed…

Following the theoretical predictions of ferromagnetism in Mn- and Co-doped ZnO, several workers reported ferromagnetism in thin films as well as in bulk samples of these materials. While some observe room-temperature ferromagnetism, others…

Materials Science · Physics 2007-05-23 C. N. R. Rao , F. L. Deepak