Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Conference Object Structural and Thermal Characterization of Ti+o Ion Implanted Ultrahigh Molecular Weight Polyethylene (uhmwpe)(American Institute of Physics, 2009) Öztarhan, Ahmet; Urkaç Sokullu, Şadiye Emel; Tıhmınlıoğlu, Funda; Kaya, N.; Ila, Daryush; Budak, S.; Nikolaev, A.In this work, Metal-Gas Hybrid Ion Implantation technique was used as a tool for the surface modification of Ultra High Molecular Weight Polyethylene (UHMWPE). Samples were Ti + O ion implanted by using Metal-Vapour Vacuum Arc (MEVVA) ion implanter to a fluence of 5x10(16) ion/cm(2) for each species and extraction voltage of 30 kV. Untreated and surface treated samples were investigated by Rutherford Back Scattering (RBS) Spectrometry, Attenuated Total Reflectance - Fourier Transform Infrared (ATR-FTIR) Spectroscopy, Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Results indicate that Ti + O ion implantation can be applied on UHMWPE surfaces successfully. ATR-FTIR spectra indicate that the C-H concentration on the surface decreased after Ti + O implantation. Thermal characterization with TGA and DSC shows that polymeric decomposition temperature is shifted after ion implantation.Article Citation - WoS: 9Citation - Scopus: 11Oxidation Behavior of C-And Au-Ion Biodegradable Polymers(Institute of Electrical and Electronics Engineers Inc., 2012) Sokullu Urkaç, Emel; Öztarhan, Ahmet; Tıhmınlıoğlu, Funda; Nikolaev, Alexey; Brown, IanBiodegradable polymers are widely used in biomedical and tissue engineering applications due to their biocompatibility and hydrolysis properties in the body. However, their low surface energy and lack of functional groups to interact with the cellular environment have limited their applications for in vivo studies. Ion beam modification is a convenient method for improving the surface properties of polymeric materials for functional biomedical applications. In the work described here, vacuum arc metal ion implantation was used to modify the composition of the near-surface region of three kinds of polymerspoly(L-lactide), poly(D, L-lactide-co-glycolide), and poly(L-lactide/caprolactone)chosen as representative of biodegradable polymers. X-ray photoelectron spectroscopy analysis was used to characterize the chemical effects of these polymers after implantation with C and with Au, and the results were compared with untreated control samples. We find that oxidation behavior is brought about for certain implantation fluences, resulting in improved surface hydrophilicity. © 2011 IEEE.Article Citation - WoS: 17Citation - Scopus: 162-D Analysis of Ge Implanted Sio2 Surfaces by Laser-Induced Breakdown Spectroscopy(Elsevier Ltd., 2008) Yalçın, Şerife; Örer, Sabiha; Turan, Raşit2-D elemental distribution of Ge in silicon oxide substrates with differing implantation doses of between 3 × 1016 cm- 2 and 1.5 × 1017 cm- 2 has been investigated by Laser-Induced Breakdown Spectroscopy (LIBS). Spectral emission intensity has been optimized with respect to time, crater size, ablation depth and laser energy. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) coupled with Energy-Dispersive X-Ray Spectroscopy (EDX) have been utilized to obtain crater depth, morphology and elemental composition of the sample material, respectively. LIBS spectral data revealed the possibility of performing 2-D distribution analysis of Ge atoms in silicon oxide substrate. EDX analysis results confirmed that LIBS is capable to detect Ge atoms at concentrations lower than 0.2% (atomic). LIBS as a fast semi-quantitative analysis method with 50 μm lateral and 800 nm depth resolution has been evaluated. Results illustrate the potential use of LIBS for rapid, on-line assessment of the quality of advanced technology materials during the manufacturing process. © 2008 Elsevier B.V. All rights reserved.Article Citation - WoS: 1Citation - Scopus: 1Electrical and Magnetic Properties of Si Ion Implanted Yba 2cu3o7-? Thin Films and Microbridges(Elsevier Ltd., 2004) Avcı, İlbeyi; Tepe, Mustafa; Serincan, Uğur; Öktem, Bülent; Turan, Raşit; Abukay, DoğanFabrication of superconducting bilayer YBa2Cu3O 7-δ (YBCO) thin film structure by Si ion implantation and properties of microbridge patterned on that are presented. YBCO thin film of 150 nm thickness was grown on single crystal (100) SrTiO3 substrate by inverted cylindrical magnetron sputtering. The sample was implanted with 100 keV, 1×1016 Si ions/cm2. Upon implantation with Si, the sample lost its electrical conductivity and diamagnetism while its crystalline structure was preserved after the annealing of the sample. The implanted ions do not alter the overall crystal structure of high temperature superconductor film. This allows the growth of epitaxial superconducting second layer YBCO film on top of the implanted area without using any buffer layer, thus providing an effective method of fabricating multilayer structures. The second layer film and the microbridge patterned by laser writing technique, showed the superconducting properties similar to those of pure YBCO base layer with a reduced critical current density.