Kaymak, Nuriye; Oz Orhan, Elif; Bayram, Ozkan; Bilge Ocak, Sema

Graphene nanosheets (Gns) obtained by the chemical vapor deposition (CVD) method have been employed for the fabrication of Graphene/Al2O3/p-type silicon (Si) structure. The Raman, scanning-electron-microscopy (SEM) and transmission-electron-microscopy (TEM) have been used to analyze the morphology and structural features of the graphene nanosheet. The dielectric features and electrical-conductivity of Graphene/Al2O3/p-type Si have been studied in the frequency range 10 kHz–400 kHz and in the voltage range, −4 V to +4 V at 300 K. The obtained experimental outcomes imply that electrical conductivity and dielectric features of Graphene/Al2O3/p-type Si were found out to be powerful functions of frequency and applied bias voltage. It can be seen that almost all of the interface states between metal and silicon contribute to modify of dielectric features of Graphene/Al2O3/p-type Si structure.

AtıfScopus6·WoS6·OpenAlex6

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Gursoy, Ozen; Colak, Murat; Tur, Kazim; Dispinar, Derya

The demand for lighter weight decreased thickness and higher strength has become the focal point in the automotive industry. In order to meet such requirements, the addition of several alloying elements has been started to be investigated. In this work, the additions of V, B, and Sr on feedability and tensile properties of A360 has been studied. A mold design that consisted of test bars has been produced. Initially, a simulation was carried out to optimize the runners, filling, and solidification parameters. Following the tests, it was found that V addition revealed the highest UTS but low elongation at fracture, while B addition exhibited visa verse. On the other hand, impact energy was higher with B additions.

AtıfScopus13·WoS12·OpenAlex14

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Kaky, Kawa M.; Sayyed, M. I.; Khammas, Abbas; Kumar, Ashok; Sakar, Erdem; Abdalsalam, Alyaa H.; Sakar, Betul Ceviz; Alim, Bunyamin; Mhareb, M. H. A.

In the present work, we fabricated a series of six glasses to be utilized in the field of radiation shielding application. Glasses have been synthesized using a melt-quenching ordinary technique. In this work, we investigated the structural properties of these glasses using Raman spectroscopy. Moreover, optical properties have been studied in the present work. The radiation attenuation ability for the present samples was also investigated and measured using transmission geometry between 81 and 964.1 keV. The mass attenuation coefficient was measured and the results were validated by the WinXcom program. Also, radiation protection efficiency (RPE) was evaluated and discussed in terms of photon energy and Bi2O3 concentration. From RPE curve, we found that the fabricated glasses can be used as effective shielding materials especially for the low energies (81-383 keV). The half value layer also was calculated and the results of this parameter showed that S6 (contains 60 mol% of Bi2O3) has the higher probability of the interaction with gamma photons, leading to less number of photons transmitted this sample and thus better photon attenuator.

AtıfScopus69·WoS72·OpenAlex76

İncele

Pat, Suat; Korkmaz, Şadan; Özen, Soner; Şenay, Volkan

In this paper, GaN thin film production was realized by thermionic vacuum arc (TVA), a plasma deposition technique, for the first time. We present a new deposition mechanism for GaN thin films with a very short production time. Microstructure properties of samples were analyzed by X-ray diffractometry. The peak at 2θ = 72.88° corresponding to GaN (0004) was detected in XRD spectra. The surface morphology of the deposited GaN films was analyzed using field emission scanning electron microscopy and atomic force microscopy. The surface properties of the produced samples are quite different. The average roughness values were determined to be 0.48 nm for GaN/PET and 1.17 nm for GaN/glass. The optical properties (i.e., refractive index and reflection) were determined using an interferometer. Moreover, the obtained optical data were compared with bulk GaN materials. The refractive indexes were measured as 2.2, 3,0 and 2,5 for the GaN/glass, GaN/PET and bulk GaN, respectively. The transparencies of the different GaN-coated substrates are nearly the same. The obtained band gap values were measured in the energy range of 3.3-3.5 eV. TVA is a novel non-reactive plasma technique for the generation of metal organic thin films. The main advantage of this method is its fast deposition rate without any loss in the quality of the films.

AtıfScopus32·WoS31·OpenAlex34

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