Document Details
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Document Type |
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Article In Journal |
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Document Title |
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Structural, EPR and optical properties of Zn0.75TM0.25O (TM = Mn, Fe, Co, Ni) aerogel nanoparticles Structural, EPR and optical properties of Zn0.75TM0.25O (TM = Mn, Fe, Co, Ni) aerogel nanoparticles |
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Subject |
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physics |
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Document Language |
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English |
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Abstract |
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ZnO nanopowders with different 3d transition metal (TM) doping (TM = Mn, Fe, Co, Ni) were
synthesized by a new protocol based on slow hydrolyse of zinc acetate dissolved in methanol and
super-critical drying in ethyl alcohol. The prepared Zn1-xTMxO (x = 0.25) nanoparticles were
characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning
calorimetry (DSC), optical absorption and electron paramagnetic resonance spectroscopy (EPR). The
results demonstrated that the TM dopant significantly affects the structural and magnetic properties of
the samples. From the XRD spectra, the lattice parameters, average crystallite size and microstrain
values were obtained. All ZnTMO nanoparticles show an expansion of the lattice parameters compared
those of the bulk samples. Unit cell volume was minimized with Fe doping and increased as the atomic
number of the dopant moved away from Fe. The XRD pattern indicates the formation of hexagonal
wurtzite phase of ZnO for all the TM dopants. Electron microscopy characterization showed that the
size of the Zn1-xTMxO particles is about 25 nm did not change significantly for the different dopants.
Optical absorption measurements show that band gap energies of the TM-doped ZnO nanoparticles
are around 3.2 eV. The Urbach energy of the ZnTMO nanopowders varies with the TM dopant. From
magnetic measurements we observed the presence of room temperature ferromagnetic order in our
TM-doped ZnO samples. EPR spectra confirm that TM ions were mainly incorporated as TM2+,
occupying the Zn2+ sites in the wurtzite structure of ZnO. Room temperature ferromagnetic order was
observed only in Ni- and Co-doped ZnO samples, whereas Mn- and Fe-doped powders showed only
antiferromagnetic and paramagnetic interactions, respectively. The correlation between the structural
and magnetic properties as a function of the TM dopant is discussed. |
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ISSN |
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1286-0042 |
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Journal Name |
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EUROPEAN PHYSICAL JOURNAL-APPLIED PHYSICS |
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Volume |
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67 |
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Issue Number |
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10 |
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Publishing Year |
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1435 AH
2014 AD |
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Article Type |
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Article |
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Added Date |
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Monday, July 31, 2017 |
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Researchers
| amor Sayari | Sayari, amor | Investigator | Doctorate | amor.sayari@laposte.net |
| Lassaad El Mir | El Mir, Lassaad | Researcher | Doctorate | |
| Hans Juergen Bardeleben | Bardeleben, Hans Juergen | Researcher | Doctorate | |
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