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Blythe, H. J.; Ibrahim, Ragheed M.; Gehring, G. A.; Neal, James R.; Fox, A. M.

doi:10.1016/j.jmmm.2004.08.008

Cited by 47 publications

(5 citation statements)

References 25 publications

(30 reference statements)

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“…However, the morphology of Mndoped ZnO nanorods (including ZMO1, ZMO2 and ZMCO) is modified very much, as can be seen in figure 1(d). According to earlier studies [36,37], the diffusion of Zn atoms into manganese oxides takes place strongly at very low annealing temperatures. Thus, the modification in morphology of the Mn-doped ZnO nanorods in our case could be understood as the strong diffusion of Zn atoms into manganese oxides created on the surface of the Mn metal as heated at high temperatures [38].…”

Section: Resultsmentioning

confidence: 89%

Raman scattering in Me-doped ZnO nanorods (Me = Mn, Co, Cu and Ni) prepared by thermal diffusion

et al. 2008

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We have investigated normal and resonant Raman scattering in Me-doped ZnO nanorods (Me = Mn, Co, Cu and Ni) prepared by thermal diffusion. Experimental results show that the normal Raman spectra consist of the conventional modes associated with wurtzite ZnO and impurity-related additional modes. Under resonant conditions, only longitudinal optical (LO) phonon scattering and its overtones are observed. The number of LO phonon lines and their relative intensity depend on the doping element and level. For the nanorods doped with Cu and Ni, we have observed LO phonon overtones up to eleventh order. This situation does not happen for the Mn-doped nanorods, which show only five LO phonon modes. By co-doping Mn and Co into the ZnO host lattice, however, the LO phonon overtones up to eleventh order are observed again. The nature of this phenomenon is explained by means of the study of XRD, TEM and photoluminescence.

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Section: Resultsmentioning

confidence: 89%

Raman scattering in Me-doped ZnO nanorods (Me = Mn, Co, Cu and Ni) prepared by thermal diffusion

et al. 2008

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“…The mechanism giving rise to ferromagnetism at such low dopant concentrations was proposed to be the carrierinduced interactions between the separated Mn atoms in ZnO, which has recently been further confirmed beyond doubt by the research group of Gamelin et al [4,5]. Room-temperature ferromagnetism in well-characterized single-phase Mn-doped ZnO has also been reported by many other researchers [4][5][6][7][8]. However, recently, Kundaliya et al proposed a different picture, wherein incorporation of Zn in Mn oxide is responsible for ferromagnetism [9].…”

mentioning

confidence: 66%

X-ray spectroscopic study of the charge state and local ordering of room-temperature ferromagnetic Mn-doped ZnO

Guo

Gupta

Sharma

et al. 2007

J. Phys.: Condens. Matter

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The charge state and local ordering of Mn doped into a pulsed laser deposited single-phase thin film of ZnO are investigated by using x-ray absorption spectroscopy at the O K-edge, Mn K-edge and L-edge, and x-ray emission spectroscopy at the O K-edge and Mn L-edge. This film is ferromagnetic at room temperature. EXAFS measurement shows that Mn(2+) replaces the Zn site in tetrahedral symmetry, and there is no evidence for either metallic Mn or MnO in the film. Upon Mn doping, the top of O 2p valence band extends into the bandgap, indicating additional charge carriers being created.

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“…Presently, microwave highpressure (MW&HP) reactors are developed due to the usefulness for reactions carried out under elevated pressures and energy saving. The MW&HP synergy gives short heating times (because of delivering high microwave power density to fl uids under pressure without contact to heater elements) leading to weakly agglomerated nanoparticles, with high crystallinity and narrow grain-size distribution (Blythe et al, 2004;Leonelli and Lojkowski, 2007). In hydrothermally microwave-grown zirconia, the stoichiometric ratio of O to Zr can vary and the material shows extended nanoporosity.…”

Section: Introductionmentioning

confidence: 99%

Combined positron-annihilation and structural studies of hydrothermally grown zirconia

Fidelus

Karbowski

Mariazzi

et al. 2012

Nanomaterials and Energy

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Nanoporous zirconia is used in gas sensors and as a membrane in high-temperature fuel cells. In the present work, positron annihilation spectroscopy and transmission electron microscopy (TEM) were performed on pure zirconia-sintered nanopowders, to determine the porosity. The ortho-positronium annihilation parameter R of zirconia samples, treated at 800°C and 700°C and annealed in oxygen–nitrogen atmosphere with different O2 contents, were obtained. The photoluminescence, positron annihilation spectroscopy, and TEM studies show presence of defects in all samples. Furthermore, the positron annihilation studies indicate a presence of large free volumes (of the order of few atomic units, at least), open towards the nanocrystals surface what was confirmed by TEM observations which detected a few types of defects such as voids within ≈2–4 interplane distances, stacking faults, terraces and point defects.

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Mechanical alloying: a route to room-temperature Ferromagnetism in bulk Zn1-xMnxO

Cited by 47 publications

References 25 publications

Raman scattering in Me-doped ZnO nanorods (Me = Mn, Co, Cu and Ni) prepared by thermal diffusion

Raman scattering in Me-doped ZnO nanorods (Me = Mn, Co, Cu and Ni) prepared by thermal diffusion

X-ray spectroscopic study of the charge state and local ordering of room-temperature ferromagnetic Mn-doped ZnO

Combined positron-annihilation and structural studies of hydrothermally grown zirconia

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