Yazar "Gencer A." seçeneğine göre listele

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  • Küçük Resim Yok
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    Magnetic characterization of LaMn2-xCoxGe 2 compounds
    (2004) Kiliç A.; Kervan S.; Gencer A.
    The structural and magnetic properties of the LaMn2-xCo xGe2 (0?x?1) compounds have been investigated by means of X-ray powder diffraction, AC susceptibility and differential scanning calorimetry (DSC) studies. All the compounds investigated crystallize in the body-centered-tetragonal ThCr2Si2-type structure with the space group I4/mmm. Substitution of Co for Mn leads to a linear decrease of the lattice constants and the unit cell volume. The samples with low Co concentration are ferromagnetic. The substitution of nonmagnetic Co for Mn weakens the strength of the molecular field acting on the Mn layers, yielding a decrease of the Curie temperature. The results lead to the construction of the partial x-T magnetic phase diagram. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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    Preparation of nano-scale magnetite Fe3O4 and its effects on the bulk Bi-2223 superconductors
    (2007) Ghazanfari N.; Kiliç A.; Özcan Ş.; Sözeri H.; Özkan H.; Gencer A.
    Abstract. Nano-scale magnetite (Fe3O4) powders were prepared from metallic iron and distilled water by wet milling technique. Magnetite powders so obtained were added to Bi1.6Pb 0.4Sr2Ca2Oy superconductor by 0.00, 0.05, 0.10 and 0.30 wt % (x), with solid state reaction method. The structural and superconducting properties were studied by x-ray diffraction, transmission electron microscopy, magnetization and magnetic susceptibility measurements. Single-phase magnetite samples with average particle size about 25 nm were obtained with the wet milling technique. Nanoscale magnetite additions up to 0.10 wt % enhance the critical current density (Jc) of the superconductor preserving the fraction of the high Tc phase Bi-2223. Magnetite additions above 0.10 wt % decrease the critical parameters (T c, Jc) and the fraction of the high Tc phase. © 2007 American Institute of Physics.