Physics / Fizik
Permanent URI for this collectionhttps://hdl.handle.net/11147/6
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Conference Object Citation - WoS: 7Citation - Scopus: 7Carbon Deposition on the Stainless Steels Substrates Using Pulsed Plasma(National Institute of Optoelectronics, 2008) Pat, Suat; Balbağ, Zafer; Cenik, I.; Ekem, Naci; Okur, Salih; Vladoiu, Rodica; Musa, GeavitWe have developed a generic method for carbon deposition method for any substrates from methane pulsed plasma. The generic method has been developed for carbon deposition on the stainless steels substrates using pulsed methane plasma. Pulsed plasma was produced at atmospheric pressure methane gas and room temperatures. Methane plasma was generated using with 25kV, 25kHz pulsed power supply. Discharge current approximately 300 mA. Stainless steels probes hold in the 32mm from the methane plasma. Probes dimensions were phi=30mm, h=8mm and 4 mm.Conference Object Citation - WoS: 3Citation - Scopus: 31/F Noise in Amorphous Silicon and Silicon-Germanium Alloys(SPIE, 2003) Johanson, Robert E.; Güneş, Mehmet; Kasap, Safa O.We report measurements of conductance noise of a-Si1-XGeX:H in two different geometries; one where the current flow is transverse to the surface and the other longitudinal to it. Because of the large increase in sample resistance in going from transverse to longitudinal conduction, it was not possible to measure both geometries at the same temperature. However, the temperature trends are compatible with a common noise source. For both geometries, alloying with up to 40% Ge reduces the noise magnitude by a factor of 50 over that found in a-Si:HConference Object Citation - WoS: 2Citation - Scopus: 1Angular Momentum Loss in Polars(Cambridge University Press, 2009) Kalomeni, BelindaWe discuss the possible angular momentum loss mechanisms in AM Her type cataclysmic variables and their corresponding mass loss rates using the observed physical parameters of them.Conference Object Phenomenological Aspects of U(1)' Models(American Institute of Physics, 2009) Demir, Durmuş AliThis talk summarizes certain phenomenological aspects of the supersymmetric models with an extra U(1) invariance broken at the TeV scale. The discussions involve the Higgs sector, CP violation, Neutrino masses and the LHC signatures.Conference Object Doubly Charged Higgsinos at Lhc(Proceedings of Science (PoS), 2008) Demir, Durmuş Ali; Frank, Mariana; Huitu, Katri; Rai, Santosh Kumar; Turan, İsmailWe review single and pair production and subsequent decay of doubly charged Higgsinos of the left-right supersymmetric model at the LHC. The novel signature is possible to separate from the MSSM and UED signal.Conference Object Signatures of Doubly-Charged Higgsinos at Colliders(American Institute of Physics, 2008) Demir, Durmuş Ali; Frank, Mariana; Huitu, Katri; Rai, Santosh Kumar; Turan, İsmailSeveral supersymmetric models with extended gauge structures predict light doubly-charged Higgsinos. Their distinctive signature at the large hadron collider is highlighted by studying its production and decay characteristics.Article Citation - WoS: 3Citation - Scopus: 3Mgb2 Superconducting Thin Films Grown by Magnetron Sputtering(National Institute of Optoelectronics, 2007) Ulucan, Savaş; Özyüzer, Lütfi; Okur, SalihIn this study, we report the growth and properties of MgB2 thin films on polycrystalline Al2O3 substrates. A composite MgB2 target was produced by MgB2 and Mg powder mixing, using a hot pressing technique. MgB2 thin films were grown on Al 2O3 substrates by d.c. magnetron sputtering, without heating the substrate. To enhance the superconducting properties of the as-grown films and to increase the crystal quality, an ex-situ anneal process was applied. The crystal structure of the thin films was determined by X-ray diffraction. The resistivity versus temperature of the deposited MgB2 thin films was studied to examine the transition temperatures of the films under various magnetic fields. The effects of the annealing temperature and annealing time on the electrical properties of MgB2 thin films are revealed.Conference Object Citation - WoS: 1Dependence of Josephson Junction Critical Current on the Deposition Rate of Yba2cu3o7-? Thin Films(American Institute of Physics, 2007) Algül, B. P.; Avcı, İlbeyi; Akram, R.; Bozbey, Ali; Tepe, Mustafa; Abukay, DoğanWe have reported the effect of YBa2Cu3O 7-δ (YBCO) thin film deposition rate on the 24 and 30 degree STO bicrystal Josephson junctions critical currents by fabricating series of junctions with different deposition rates. Dependence of YBCO thin film structures on the deposition rate was investigated. We have observed that the critical currents of junctions are strongly affected by the thin film deposition rate.Conference Object Growth and Characterization of Carbon Nanostructures(American Institute of Physics, 2007) Selamet, Yusuf; Yüce, GörkemCarbon nanostructures were grown by arc-discharge method and characterized by SEM, AFM, STM, and XRD techniques. We observe broadening in the radial distribution of nanofibers grown with Co and Ni application. The nanofibers grown with Co/Ni application were straighter and shorter in length than nanofibers without Co/Ni application. This might be due to catalyst particle poisoning resulting in termination of the growth process earlier than expected.Conference Object Citation - WoS: 1Citation - Scopus: 1Minority Carrier Properties of Microcrystalline Silicon Thin Films Grown by Hw-Cvd and Vhf-Pecvd Techniques(National Institute of Optoelectronics, 2005) Okur, Salih; Göktaş, Oktay; Güneş, Mehmet; Finger, Friedhelm; Carius, ReinhardOpto-electronic properties of μc-Si:H films prepared by hot-wire/catalytic chemical vapor deposition (HWCVD) and very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) techniques with various silane concentrations (SC) have been investigated using Raman spectroscopy, the steady-state photocarrier grating technique (SSPG), and the steady-state photoconductivity (SSPC). A correlation between the minority carrier transport properties and the microstructure has been found, using the dependence of the diffusion length (Ld) on the SC and Raman intensity ratio (I c RS) representing crystalline volume fractions. I C RS changes from 0.22 to 0.77. Ld increases with increasing Ic RS. It peaks around 0.5 with a maximum value of 270 nm, then decreases. Similar dependences of Ld on I C RS were obtained for films prepared by both HWCVD and VHF-PECVD. However, the grating quality factor measured on highly crystalline HWCVD films is substantially smaller than that found for VHF-PECVD films, indicating a relatively higher surface roughness present in the highly crystalline HWCVD films.