Browsing by Author "Aycibin, Murat"

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Ab Initio Study of Li2cata2o7 Compound: Electronic and Optical Properties for Three Phases
(Tubitak Scientific & Technological Research Council Turkey, 2019) Aycibin, Murat
The Li2CaTa2O7 compound belongs to the Ruddlesden-Popper family of layered perovskites. First principle approximation was used to investigate the electronic band structure and optical properties of the compound for three phases. Independent of the studied compound's structural type, Li2CaTa2O7 has semiconductor behavior and direct transition. In addition, the forbidden energy band gap of the compound decreases with rising temperature, as expected. Furthermore, the 3d orbital of Ca contributes to the conduction band due to the crystal field effect. Moreover, the optical response of the chosen axes of the compound to incoming electromagnetic rays varies with phase transition.
Ab-Initio Calculations of Physical Properties of Alkali Chloride Xcl (X = K, Rb and Li) Under Pressure
(Elsevier, 2015) Erdinc, Bahattin; Secuk, Mehmet Nurullah; Aycibin, Murat; Gulebagan, Sinem Erden; Dogan, Emel Kilit; Akkus, Harun
Structural properties, electronic band structure, real and imaginary parts of complex dielectric function of alkali chloride XCl (K, Rb and Li) compounds were investigated under various pressures using first principles calculations. Moreover, Gibbs free energies were also calculated at those pressures. Calculated results of the Gibbs free energy show that LiCl does not show any structural phase transition. However, structural phase transitions of KCl and RbCl occur from NaCl (B1) to CsCl (B2) at 4.5 and 1.7 GPa pressures, respectively. The electronic band gaps under pressure were also calculated. The calculated physical properties of these compounds are compared with the previous theoretical and experimental results and a good agreement was observed. (c) 2015 The Authors. Published by Elsevier B. V. This is an open access article under the CC BY-NC-ND license.
Ab-Initio Study of Csgecl3 Compound in Paraelectric and Ferroelectric Phases
(Taylor & Francis Ltd, 2016) Erdinc, Bahattin; Secuk, Mehmet Nurullah; Aycibin, Murat; Gulebagan, Sinem Erden; Dogan, Emel Kilit; Akkus, Harun
Structural optimization, electronic energy band structure, density of states, optical, lattice dynamic and thermodynamic properties of CsGeCl3 compound in paraelectric and ferroelectric phases were investigated using the DFT in the GGA and LDA approximations. The obtained results of CsGeCl3 crystal were compared with the available theoretical and experimental results and have been found to be in good agreement with these results.
Comprehensive Theoretical Investigation of Electronic, Structural, Optical, Elastic, and Thermodynamic Properties of Orthorhombic Srta2o6 Compound
(Canadian Science Publishing, 2022) Erzen, Mehmet; Aycibin, Murat; Akkus, Harun
The structural, optical, dynamic, elastic, and thermodynamical properties of orthorhombic SrTa2O6 were computed using density functional theory via two computation codes, namely Wien2k and ABINIT. The findings reveal that SrTa2O6 is a wide bandgap semiconductor with 4.6 eV using the TB-mBJ approximation. The results of bulk modulus, shear modulus, Young's modulus, Poisson's ratio, anisotropy factors, and Debye's temperature were obtained and discussed in detail. Moreover, The ductile behavior and structural stability mechanism were also explained.
Dft Study of Cscaf3: Eu
(Gazi Univ, 2016) Aycibin, Murat; Erdinc, Bahattin
In this article, we studied some changes on structural, optical and electronic properties of CsCaF3 when it is doped with Eu atom. All properties of doped CsCaF3 are calculated using the full potential linearized augmented plane wave to the density functional theory. The exchange-correlation potential is evaluated using generalized gradient approximation. This work presents comparison of undoped and doped with Eu atoms of CsCaF3 compound. Moreover, we show that CsCaF3: Eu has indirect band gap with the Generalized Gradient Approximation and doping makes energy band gap values decreases.
Electronic Structure and Lattice Dynamics of Baceo3 Compound in Cubic Phase
(Springer, 2014) Aycibin, Murat; Erdinc, Bahattin; Akkus, Harun
In this paper, electronic band structure, total density of states, and optical, lattice dynamic and thermo-dynamic properties of BaCeO3 compound in cubic phase were investigated using density functional theory within the generalized gradient approximation. The calculated lattice constant is consistent with the experimental result. In cubic phase, BaCeO3 has a semiconductor character with 2.17 eV band gap.
The Electronic, Structural, and Optical Properties of Canb2o6 Compound: Theoretical Study
(Wiley-v C H verlag Gmbh, 2021) Duman, Ubeyt; Aycibin, Murat; Ozdemir, Omer Faruk
Based on the density functional theory (DFT) as incorporated in the Wien2k package, the lattice parameters and atomic position of calcium niobate (CaNb2O6) were optimized. Furthermore, the electronic, optical, and structural properties of the relaxed compound were calculated. Relaxed calcium niobate presents a direct band gap with 3.5 eV, which makes it a good candidate for photovoltaic applications. The DFT calculation reveals that the O atoms make the major contributions in the valence band, while Nb and Ca atoms are the dominant contributors in lower and upper portions of the conduction band, respectively. Moreover, the optical properties of compounds such as refractivity, dielectric constant, reflectivity, etc. are calculated and discussed in detail.
Exploring Electronic, Structural, Optical, and Elastic Properties of Mgx2o6 (X = Ta, Nb) Compounds for Photovoltaic and Optoelectronic Applications: First Study Effort
(indian Assoc Cultivation Science, 2024) Aycibin, Murat; Celebi, Mustafa; Erzen, Mehmet; Akkus, Harun
In this study, the structural, optical, and elastic properties of tetragonal MgTa2O6 and orthorhombic MgNb2O6 were determined using the Wien2k and ABINIT computational programs with the aid of density functional theory. The results imply that both compounds are classified as wide band gap semiconductor with 4.143 eV (for MgTa2O6) and 3.653 eV (for MgNb2O6) with PBEsol-GGA + TB-mBJ approximation. The findings of bulk modulus, shear modulus, Young modulus, Poisson's ratio, and anisotropy factors were determined and discussed in detail. The ductile behavior and the mechanism of structural stability were also explained.
First-Principles Calculation of the Electronic and Optical Properties of Birho3 Compound
(Amer inst Mathematical Sciences-aims, 2017) Aycibin, Murat; Ece, Naciye
Nowadays, most of the ferroelectric materials have lead element in their formula. Having the lead element as an ingredient is hazardous both human life and environment. For safety reason, we have to replace lead-based compound with lead-free based one. Bismuth-based ferroelectric materials are one of the lead-free ferroelectric compounds. In this paper, we studied BiRhO3 compound belongs to bismuth-based family. We calculated and analyzed BiRhO3 physical properties such as electronic, structural and optical. According to our result, BiRhO3 is classified as a semiconductor with narrow band gap, 0.3 eV, with indirect transition. Moreover, its optical constant depends on choosing axes due to structure type.
Influence of Annealing Process on Structural, Optical and Electronic Properties of Nano-Structured Zno Films Synthesized by Hydrothermal Technique: Supported by Dft Study
(Elsevier, 2022) Majeed, Mahmood H.; Aycibin, Murat; Imer, Arife Gencer; Muhammad, Ali M.; Kareem, Mahmood M.
The annealing temperature effect on the physical properties of zinc oxide (ZnO) nanorods is experimentally and theoretically investigated. Different diagnostics techniques such as XRD, UV-Vis, SEM, and Hall effect measurements were employed to analyze the influence of annealing temperature on the structural, optical, and electrical properties of ZnO nanorods films. Additionally, Density Functional Theory (DFT) was also applied to calculate ZnO's lattice parameters, energy gap, and optical properties depending on annealing temperature. Experimental results show that the variation of the optical band gap of the fabricated samples has the same behavior within the theoretical calculation. X-ray diffraction (XRD) results reveal that the pure film is crystallized in the hexagonal phase of ZnO with the miller plane (00 2).The crystallite size is affected by annealing temperature. The field emission scanning electron microscopy (FESEM) shows nanorods formation on the surface of the films. The transmittance properties of the studied films are dependent on the annealing temperature in the ZnO films from UV-Vis data, confirming the band gap's widening effect with annealing. Overall, the experimental and theoretical findings support each other.
Influence of Substrate Temperature and Mn/Y Co-Doping Concentration on the Morphological, Structural and Optical Properties of Cuo Nanostructured Film Deposited by the Spray Pyrolysis Method
(Elsevier, 2025) Hussein, Balen; Imer, Arife Gencer; Aycibin, Murat
In this work, the effect of substrate temperature (ST) during deposition and dopant amount of Mn (1,3,5, and 7 %) and Y(3 %), (Mn/Y), on the physical properties of copper oxide (CuO) the nanostructured film were analyzed using different diagnostic tools. The pure and (Mn, Y) co-doped CuO thin films were deposited by the spray pyrolysis method, which is effective and easy to apply for any substrate. Deposited pure and (Mn,Y) co-doped CuO nanostructured films were investigated by X-ray diffraction (XRD), UV-Vis spectroscopy, and Field emission scanning electron microscopy (FESEM) techniques to analyze the influence of ST and co-doping on the structural, morphological, and optical properties of prepared films. The FESEM is used to visualize nano- structures on the surface of the film. Also, it is observed that the surface morphology of CuO film changes from a spherical-like to a nanocloumnar-like structure with increasing substrate temperature. The XRD diffractograms confirm the monoclinic crystal structure of CuO, in polycrystalline nature for all deposited films. UV-Vis spectra suggest changing the optical absorbance and the band gap of the pure and Mn/Y co-doped CuO nanostructured films. In the first investigation of this study, the better substrate temperature was obtained as 400 degrees C according to results. In the second part, the effect of Y and Mn doping with different content was analyzed for the CuO film deposited at the chosen ST of 400 degrees C. There is no observable crystalline structure variation in the XRD pattern, but the size of nanostructure and dislocation density are varied with Mn/Y co-doping. FESEM micrographs confirm the impact of the co-doping concentration on the size, shape, and surface properties of CuO nano- structured film. In addition, the optical band gap increases with Mn doping up to 3 % of Mn content and it was determined as 2.69 eV for the sample 3Mn/Y@CuO nanostructured film. The obtained results suggest that the substrate temperature has an important impact on the physical properties of the spray deposited CuO nano- structured film, and the structural, optical, and surface properties of the CuO nanostructured films may be engineered by Mn/Y doping concentration.
The Investigation of Doping Effects on Forbidden Band Gap Value of Zno: Experimental and Theoretical Studies
(2021) Majeed, Mahmood Hameed; Aycibin, Murat
Tez çalışmamızda, deneysel ve teoretik yöntemler kullanılarak zink oksit bileşiğinin yasak enerji bant aralığının katkı maddesi ile nasıl değiştiğini inceledik. Katkı elementleri olarak Mg, Y ve Mg-Y eş katkılı olarak kullanıldı. Deneysel kısımda, Autoclave methodu, hidrotermal tekniği bir türü, kullanılarak katkılı örnekler elde edildi. Bu kısımda kullanılan autoclave metodondan sonra yapılan tavlamanın, hazırlanan örneklerin soğurma sonuçlarında bir etkisi olmadığı görüldü. Soğurma grafikleri bize, katkı malzemesine bağlı olarak örneklerin soğurma grafiklerinin farklı olduğunu söylemektedir. ZnO bileşiği Mg ile katkılandığı zaman, soğurma mavi bölgeye kayarken, Y veya Mg-Y ile katkılandığı zaman soğurmanın kırmızı bölgeye kaydığı görülmüştür. Geçirme grafiği ise soğurma grafiğinin onaylayacak şekildedir. Teorik kısımda, supercell oluşturulup, oluşturulan bu supercell de bir veya iki tabe Zn elementi, katkılanacak durumu göre, Mg, Y veya Mg-Y ile yerdeğiştirlmiştir. Bu şekilde elde edilen örneklerin yasak enerji bant yapılarındaki değişmeye bakılmıştır.
Investigation of Electronic and Optical Characteristics of the Canb2o6 Compound at Room Temperature
(2020) Duman, Übeyt; Aycibin, Murat
Bu tez çalışmamızda, CaNb2O6 kristalinin oda sıcaklığında elektronik ve optik özellikleri Yoğunluk Fonksiyonel Teorisine dayanan WİEN2k hesaplama programını kullanılarak incelendik. CaNb2O6 kristalinin hacim optimizasyonu sonucunda, Wien2k programında bulunan 4 tane potansiyelden biri olan PBE-GGA en iyi sonucu vermiştir. Seçilen potansiyel kullanılarak CaNb2O6 kristalinin elektron yoğunluğu, bant yapısı, durum yoğunluğu (DOS) ve optik özellikleri hesaplandı. Elde edilen yasak enerji bant değeri CaNb2O6 kristalinin geniş aralıklı yarı iletken malzeme olduğunu göstermiştir.
Li2srta2o7 Compound: Theoretical Study of Electronic and Optical Properties
(Gazi Univ, 2019) Aycibin, Murat
The electronic structures and optical properties of Li2SrTa2O7 belongs Ruddlesden-Popper layered perovskite family are studied by first-principles self-consistent local density calculations in its orthorhombic and tetragonal phases. The exchange-correlation potential were introduced within a framework of the generalized gradient approximation (GGA). In both phases, the conduction band minimum is at the zone center while the valance band is located at H and N high symmetry points for orthorhombic and tetragonal phases, respectively. The dynamic dielectric function, optical properties such as reflectance, refractivity and extinction coefficient for two phases are reported for energy range 0-50 eV. The variation in electronic and optical properties can be interpreted to attribute to higher symmetry, coordination number or Li, Sr and Ta atoms and packing density in tetragonal phase than in orthorhombic phase.
Linear Optical Properties of Ferroelectric Semiconductor Bi2nbo5f Crystal
(Taylor & Francis Ltd, 2015) Duran, Duygu; Erdinc, Bahattin; Aycibin, Murat; Akkus, Harun
In this paper, we investigated the electronic band structure, total and partial density of states and optical properties of ferroelectric Bi2NbO5F structure with space group Pca2(1) using the density functional theory under the generalized gradient approximation. Our computational results show that Bi2NbO5F compound is a ferroelectric semiconductor with a narrow band gap. Due to anisotropy, linear optical properties of component were calculated for three crystallographic directions.
Mn ve Y ile Katkılanmış Cuo'nun Yasak Bant Aralığının İncelenmesi
(2021) Zangana, Balen Husseın Ahmed; Aycibin, Murat
Bu tez çalışmasının amacı, saf, mangan ve itrium elementleri ile katkılanan CuO'nun yasak enerji bant aralığını araştırmaktır. Katkı olarak kullanılan elementlerin, CuO'nun özelliklerine etkisi hem deneysel hem de teorik methodlar kullanılarak incelenmiştir.Deneysel olarak, cam altlık üzerine katkısız ve katkılı CuO film işlemi spray piroliz tekniği ile yapılmıştır. Saf ve katkılı CuO ince filmlerin optik bant aralığı UV-VIS spektroskopisi ile incelenmiştir. Alınan geçirgenlik grafikleri katkı elementlerinin CuO'nun geçirgenliğini etkilediğini ortaya koymuştur.Teorik olarak yapılan çalışma da CuO bileşiğinin direkt band geçişine sahip olduğu görülmüştür. Aynı zaman da teorik çalışmalar, deneysel olarak elde edilen bulguları destekler niteliktedir.
Physical Properties of Rbau Compound
(Elsevier Science Bv, 2014) Aycibin, Murat; Dogan, Emel Kilit; Gulebaglan, Sinem E.; Secuk, M. Nurullah; Erdinc, Bahattin; Akkus, Harun
In this paper, we investigated electronic, optic, elastic, dynamic and thermodynamic properties of RbAu compound by density functional theory within the generalized gradient approximation. The calculated static value of real part of dielectric constant is 6.7. The calculated electronic band structure of RbAu shows that RbAu is a semiconductor with an indirect band gap of 0.36 eV. Besides, RbAu obeys mechanical stability and it demonstrates elastic anisotropy. 540K is classical limit for specific heat of RbAu. (C) 2014 The Authors. Published by Elsevier B.V.
Physical Properties of Ultrasonically Spray Deposited Yttrium-Doped Sno2 Nanostructured Films: Supported by Dft Study
(Springer Heidelberg, 2021) Kaya, Esra; Ugur, Ali; Imer, Arife Gencer; Aycibin, Murat; Ocak, Yusuf Selim
The physical properties of ultrasonically spray deposited Yttrium (Y) doped tin dioxide (SnO2) are experimentally and theoretically investigated. The different diagnostics techniques such as X-ray diffraction (XRD), UV-Vis, scanning electron microscopy (SEM) and Hall effect measurements were performed to analyze the influence of yttrium doping ratio on the structural, optical and electrical properties of Y-doped SnO2 nanostructured films. Additionally, density functional theory (DFT) is applied to calculate and check the energy gap, lattice parameters and optical properties of SnO2 with different Y doping ratios. Super cell of Y-doped SnO2 was formed using Wien2k, and analyzed to physical properties of un-doped and Y doped stoichiometry with different ratios. Theoretical results are in agreement with the experimental results and the literature reports. Experimental results show that the optical band gap of fabricated sample increases with the increasing the Y doping amount in the tin dioxide film. The same tendency of energy band gap is observed with DFT calculation for Y-doped SnO2 compound. Theoretical results also show that the lattice parameter is nearly the same for pure and Y-doped SnO2 case, attributed to a change in the stoichiometry owing to metal doping. XRD results reveal that the all fabricated films are polycrystalline in the tetragonal Bravais lattice of tin dioxide(,) and the crystallite size, the crystalline orientation are affected by the Y doping level. The nanosized grains of the produced films are manipulated with increasing the Y dopant confirmed by the SEM. Y doped nanostructured films show the higher optical transmittance about 90% in ultra-violet region. Optical band gap gets widen from 3.689 to 3.810 eV with increasing the dopant amount. From Hall effect results, lower resistivity, higher carrier concentration and high enough mobility have been achieved by Y doping for the sample 5 at% Y:SnO2 based TCO film. The obtained results declared that Yttrium doping has an important effect on the optoelectronic properties, in particular, transparency and conductivity of SnO2 nanostructured film.
Structural and Electronic Properties of Zincblende Phase of Tl X Ga1-X as Y P1-Y Quaternary Alloys: First-Principles Study
(Sciendo, 2013) Gulebaglan, Sinem E.; Dogan, Emel K.; Aycibin, Murat; Secuk, Mehmet N.; Erdinc, Bahattin; Akkus, Harun
Using the first-principles band-structure method, we have calculated the structural and electronic properties of zincblende TlAs, TlP, GaAs and GaP compounds and their new semiconductor Tl (x) Ga1-x As (y) P1-y quaternary alloys. Structural properties of these semiconductors are obtained with the Perdew and Wang local-density approximation. The lattice constants of Tl (x) Ga1-x As, Tl (x) Ga1-x P ternary and Tl (x) Ga1-x As (y) P1-y quaternary alloys were composed by Vegard's law. Our investigation on the effect of the doping (Thallium and Arsenic) on lattice constants and band gap shows a non-linear dependence for Tl (x) Ga1-x As (y) P1-y quaternary alloys. The band gap of Tl (x) Ga1-x As (y) P1-y , E (g) (x, y) concerned by the compositions x and y. To our awareness, there is no theoretical survey on Tl (x) Ga1-x As (y) P1-y quaternary alloys and needs experimental verification.
Study of the Electronic, Structure and Electrical Properties of Mg and Y Single Doped and Mg/Y Co-Doped Zno: Experimental and Theoretical Studies
(Elsevier Gmbh, 2022) Majeed, Mahmood Hameed; Aycibin, Murat; Imer, Arife Gencer
In the study, the experimental and theoretical tools were employed to investigate an impact of the Mg and Y single doping and Mg/Y co-doping on the physical properties of Zinc oxide nanorods. For this aim, ZnO nanoarray modified with alkaline-earth metal (Mg) and rare-earth metal (Y) were prepared using hydrothermal methods. In experimental part, the effects of single and co doping on the structural, morphological, electrical and optical properties of prepared samples were characterized by X-ray diffraction, UV-vis spectroscopy, Hall Effect, and Field emission scanning electron microscopy techniques. The presence of the nanorods were confirmed by FESEM images. The XRD measurement confirms that all prepared samples have hexagonal structure of ZNO with polycrystalline property. Y doping increase electrical conductivity of ZnO, while ZnO doped with Mg has low electrical conductivity as compared with pure cases. Optical bandgap of the ZnO varies dependent on the selected doping process: 'single doping' or 'co doping'. In the theoretical part of the study, the dopant effects on properties of ZnO were studied using density functional theory. Analyzing electronic band structure of prepared samples reveals that the energy band of Mg doped ZnO is higher than their undoped case while it is smaller for Y and Mg-Y co-doped ZnO compounds consisted with the experimental findings.