Browsing by Author "Arda, Lütfi"

Now showing 1 - 2 of 2

Citation - WoS: 7
Citation - Scopus: 9
Electron Spin Resonance and Photoluminescence Studies of Co/Mg Co-Doped Zno Nanoparticles
(Wiley, 2023) Arda, Lütfi; Karatas, Ozgul; Alphan, Mehmet Can; Özugürlü, Ersin
Zn0.95-xMg0.05CoxO (x = 0.01-0.05 with an increment of 0.01) nanoparticles were synthesized by using the sol-gel technique to analyze structural and magnetic properties. The single phase was observed in the X-ray diffraction measurements. To examine the surface morphology, elemental compositions, crystal quality, defect type, density, and magnetic behavior of the nanoparticles, SEM, energy dispersive X-ray analysis (EDX), PL, and ESR were used, respectively. The PL has ultraviolet and a broad emission band including violet and a blue spectral region corresponding to the defect-related and excitonic emissions. These emissions were strongly dependent on the synthesize condition and doping element and ratio. The effect of cobalt concentration on the line widths of pike to pike (Delta HPP) and the g-factor of ESR spectra were investigated. By comparing the results of the ESR and PL measurements, it was determined which defect with a given g-factor was responsible for the corresponding PL emission band. In addition, ESR spectra of Mg/Co co-doped ZnO nanoparticles with different cobalt concentrations recorded at room temperature were presented. Since Mg/Co co-doped ZnO nanoparticles reveal ferromagnetism at RT, they could be an appropriate material for new devices in spin-based technologies.
Citation - WoS: 3
Citation - Scopus: 4
Fabrication and Characterization of Tiox Based Single-Cell Memristive Devices
(Iop Publishing Ltd, 2023) Özkal, Bünyamin; Kazan, Sinan; Karataş, Özgül; Ekinci, Gökhan; Arda, Lütfi; Rameev, Bulat Z.
Nowadays, remarkable progress has been observed in research into neuromorphic computing systems inspired by the human brain. A memristive device can behaviorally imitate the biological neuronal synapse therefore memristor-based neuromorphic computing systems have been proposed in recent studies. In this study, the memristive behaviors of titanium dioxide sandwiched between two platinum electrodes were investigated. For this purpose, three SiO2/Pt/TiOx/Pt thin films with 7.2 nm, 40 nm, and 80 nm TiOx metal-oxide layers were fabricated using a pulsed laser deposition technique. The fabrication process, structural properties, photoluminescence properties and electrical transport characterization of each thin film have been investigated. All thin films were analyzed in terms of the film stoichiometry and degree of oxidation using high-resolution x-ray photoelectron spectroscopy. By measuring the layer thickness, density, and surface roughness with the x-ray reflectivity technique, by analyzing the structural defects with photoluminescence spectroscopy and by characterizing the quasi-static electrical properties with the conventional two probes technique, we have shown that the fabricated memristive devices have bipolar digital switching properties with high ROFF/RON ratio. This type of switching behavior is applicable in random access memories. Experimental current-voltage behavior in the form of pinched hysteresis loop of the films have been modelled with generalized memristor model.