Yazar "Bolivar, Peter Haring" seçeneğine göre listele

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    Electromagnetic properties in the structure of Cerium-Copper substituted barium hexaferrite
    (Elsevier, 2022) Yener, Tuba; Araz, Isa; Kirsoy, Ahmet; Yalcin, Orhan; Okutan, Mustafa; Bolivar, Peter Haring
    In this study Ce3+ -Cu2+ doped barium hexaferrite Ba-0.5 Ce0.5CuFe11O19 composite sample was synthesized by a conventional method and barium hexaferrites/CeO2 phase composition, X-Ray Diffractometer were examined. Sample morphology was observed by SEM. A VSM was used to analyze the magnetic properties of the ferrites. Complex permittivity, permeability, reflection loss, absorption loss and shielding effectiveness were analyzed by using a VNA measuring the transmission/reflection coaxial airline method. The phase changes of the crystal structure because of the effect of Ce3+ ions into Ba2+ site and Cu2+ ions into Fe3+ areas were investigated. The resulting composition in these two resonance phases has a maximum absorption loss value at similar to 6.48 GHz and similar to 11.25 GHz and a maximum reflection loss value at the same frequencies. In this synthesized composition structure, it has been observed that it has a maximum reflection loss value of approximately -22.2dB and the highest shielding effectiveness value of 33.3 dB at microwave frequency 11.25 GHz. (c) 2022 Elsevier B.V. All rights reserved.
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    Fullerene C60: Dielectric and elastic properties of E8 nematic liquid crystal
    (Elsevier, 2024) Okutan, Mustafa; Ozturk, Muhittin; Yesilot, Gursel; Yalcin, Orhan; Bolivar, Peter Haring
    This study presents a comprehensive analysis of the impact of Fullerene C60 doping on the dielectric and elastic behavior of E8 coded nematic liquid crystals. By investigating the underlying mechanisms, we unveil how Fullerene C60 can effectively modify the properties of nematic liquid crystals, particularly their dielectric and elastic characteristics. Through the analysis of Cole-Cole plots and semicircle plots, we gain valuable insights into the suitability of an equivalent electronic circuit model, thereby holding promise for liquid crystal-based devices with improved performance and functionality in electrical circuit applications. Furthermore, our results demonstrate that the presence of Fullerene C60 induces higher splay elastic constant (K11) values in doped nematic liquid crystals, attributed to an increase in the sample's threshold voltage. Moreover, the presence of Fullerene C60 fosters strong elastic interactions in the liquid crystal system due to surface anchorage, resulting in an elevation of its elastic energy.
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    Impedance characterization of hydrothermally synthesized nickel zinc ferrite nanoparticles for electronic application
    (Elsevier, 2024) Okutan, Mustafa; Ozturk, Muhittin; Okutan, Sonay; Yesilot, Gursel; Yalcin, Orhan; Bablich, Andreas; Bolivar, Peter Haring
    This study comprehensively investigates the structural, morphological, dielectric, and conductivity properties of Ni0.5Zn0.5Fe2O4 nanoparticles synthesized through a hydrothermal method, focusing on their suitability for technological applications. The nanoparticles exhibited a cubic structure with an average grain size of approximately 19 nm. The dielectric properties were analyzed with respect to frequency and temperature, showcasing behaviors consistent with Maxwell-Wagner and Koop's theories. The dielectric plane plots, corresponding to the impedance circuit in the Smith Chart, were found to align with the Davidson-Cole relaxation model. Moreover, the conductivity properties adhered to the Jonscher Power law, resembling conductive properties akin to semiconductors in accordance with the band theory. Notably, the s parameter, indicative of the DC conduction mechanism, displayed temperature-dependent variations, suggesting compatibility with the small polar and correlated hopping barrier conduction models. The thermal activation energies of the Ni0.5Zn0.5Fe2O4 nanoparticles at 102, 103, 104, 105, and 106 rad/s frequencies have been recorded at 0.115, 0.141, 0.157, 0.133 and 0.121 eV, respectively. The experimental results strongly suggest that Ni0.5Zn0.5Fe2O4 nanoparticles hold promise as an inspiring material for electronic circuit applications.