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2019

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Articles 1231 - 1260 of 1318

Full-Text Articles in Physics

Structural Phase Transitions And Electronic Properties Of Li2o2 And Na2o2 Under High Pressure For Co2 Capture Application, Pornmongkol Jimlim Jan 2019

Structural Phase Transitions And Electronic Properties Of Li2o2 And Na2o2 Under High Pressure For Co2 Capture Application, Pornmongkol Jimlim

Chulalongkorn University Theses and Dissertations (Chula ETD)

Since pressure induces exotic chemical and physical properties of materials, investigation of the high-pressure effect on structural phase transition and the related properties is paramount. Structural phase transitions and electronic properties of Li2O2 and Na2O2 under high pressure were investigated using first-principles calculations based on the density functional theory. Structural phase transitions of Li2O2 up to 500 GPa were predicted at ~75 GPa from the P63/mmc to the P21 structures and at ~136 GPa from the P21 to the P21/c structures. The calculated band gaps of all phases increase with elevated pressure. At 11 and 40 GPa, the band gaps …

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New Perspectives On The Schrödinger-Pauli Theory Of Electrons: Part I, Viraht Sahni Jan 2019

New Perspectives On The Schrödinger-Pauli Theory Of Electrons: Part I, Viraht Sahni

Publications and Research

Schrödinger-Pauli (SP) theory is a description of electrons in the presence of a static electromagnetic field in which the interaction of the magnetic field with both the orbital and spin moments is explicitly considered. The theory is described from the new perspective of the individual electron via its equation of motion or ‘Quantal Newtonian’ first law. The law is in terms of ‘classical’ fields whose sources are quantum mechanical expectation values of Hermitian operators taken with respect to the system wave function. The law states that each electron experiences an external and an internal field, the sum of which vanish. …

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New Perspectives On The Schrödinger-Pauli Theory Of Electrons: Part Ii: Application To The Triplet State Of A Quantum Dot In A Magnetic Field, Marlina Slamet, Viraht Sahni Jan 2019

New Perspectives On The Schrödinger-Pauli Theory Of Electrons: Part Ii: Application To The Triplet State Of A Quantum Dot In A Magnetic Field, Marlina Slamet, Viraht Sahni

Publications and Research

The Schrödinger-Pauli (SP) theory of electrons in the presence of a static electromagnetic field can be described from the perspective of the individual electron via its equation of motion or 'Quantal Newtonian' first law. The law is in terms of 'classical' fields whose sources are quantum-mechanical expectation values of Hermitian operators taken with respect to the wave function. The law states that the sum of the external and internal fields experienced by each electron vanishes. The external field is the sum of the binding electrostatic and Lorentz fields. The internal field is the sum of fields representative of properties of …

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Study Of A = 100-150 Superdeformed Mass Region By Using Two-Parameterformula, Vidya Devi, Jagjit Singh Matharu Jan 2019

Study Of A = 100-150 Superdeformed Mass Region By Using Two-Parameterformula, Vidya Devi, Jagjit Singh Matharu

Turkish Journal of Physics

Empirical formulae of rotational spectra consisting two parameters, such as single-term energy formula, E = aJb for spin J , and ab formula, were used to study the different features of superdeformed band in A = 100-150 mass region nuclei. The nuclear kinematic and dynamic moment of inertia for the ground-state rotational bands were calculated for this purpose and both showed gradual rise with rotational frequency. The study of ΔI = 2 staggering effects in the γ-ray energies, where the two sequences J = 4i; 4i + 1 and J = 4i + 2, (i = 0; 1; ...) are …

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Effects Of Cooling Rate On The Atomic Structure And Glass Formation Process Of Co90 Zr10 Metallic Glass Investigated By Molecular Dynamics Simulations, Murat Çeltek, Sedat Şengül Jan 2019

Effects Of Cooling Rate On The Atomic Structure And Glass Formation Process Of Co90 Zr10 Metallic Glass Investigated By Molecular Dynamics Simulations, Murat Çeltek, Sedat Şengül

Turkish Journal of Physics

In this study, the atomic structure and the glass formation process of Co90 Zr10 metallic glass alloy were studied by molecular dynamic simulation based on the embedded atom method using four different cooling rates. The average atomic volume and the potential energy of the system were observed to be strongly dependent on the cooling rate during rapid solidification, and the glass transition temperature decreased with decreasing cooling rate. The radial distribution functions and the structure factors derived from molecular dynamics simulations at 300 K agreed well with the experimental and other molecular dynamics results. The coordination numbers calculated at 300 …

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Design And Test Of An Apparatus For Transient Measurements Of The Thermalconductivity And Volumetric Heat Capacity Of Solids, Florian Gather, Ekrem Güneş, Peter J. Klar Jan 2019

Design And Test Of An Apparatus For Transient Measurements Of The Thermalconductivity And Volumetric Heat Capacity Of Solids, Florian Gather, Ekrem Güneş, Peter J. Klar

Turkish Journal of Physics

Knowledge of the thermal conductivity (κ) of solids is crucial for all thermoelectric devices. A new approach in transient measurement to determine this value as well as electric conductivity (σ) and the Seebeck coefficient (S) is presented here. This approach can be combined with current steady-state methods. A cylindrical sample is mounted between two heat-flux sensors that can be heated or cooled at their outer ends. The input signals defining the heat fluxes at the sensors can be any arbitrary function of time, although some waveforms yield more valid results. The method is evaluated by employing a one-dimensional numerical model …

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Autonomous Piston Engine Guided By The Transduction Of Radiation Pressure Inoptomechanical Brownian Motors, Yusuf Gül Jan 2019

Autonomous Piston Engine Guided By The Transduction Of Radiation Pressure Inoptomechanical Brownian Motors, Yusuf Gül

Turkish Journal of Physics

We consider the autonomous piston engine in a coupled cavity scheme in an optomechanical setup. Treating the radiation field as working fluid, we investigate the transduction of virtual photons due to ground state excitations. Rabi-like energy splittings and Casimir effect are shown by avoided crossing in the eigenfunction spectrum. Second order coherence functions are employed to analyze the bunching of the cavity and mechanical mode in optomechanical implementation of Brownian motors. The imbalance in occupation numbers of the working modes is investigated for the power for work extraction. We explore the guidance of the radiation field in work extraction. We …

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Modified Newton's Gravitational Law From Deformed Poisson Bracket, Ch'ng Han Siong Jan 2019

Modified Newton's Gravitational Law From Deformed Poisson Bracket, Ch'ng Han Siong

Turkish Journal of Physics

In this paper, we obtain the modified Newton's gravitational law from deformed Poisson bracket motivated by the generalized uncertainty principle. The modified Newton's gravitational law that we obtain contains a term that plays an important role only in the regime of first order in $\bar{\beta}$. In the ordinary situation or condition, the modified Newton's gravitational law reduces to the conventional Newton's gravitational law.

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Synthesis, Characterization, And Magnetic Properties Of Nanosizedzn0.5co0.5erxfe2-Xo4 Prepared By Coprecipitation Method, Zouheir Bitar, Doaa El-Said Bakeer, Ramadan Awad Jan 2019

Synthesis, Characterization, And Magnetic Properties Of Nanosizedzn0.5co0.5erxfe2-Xo4 Prepared By Coprecipitation Method, Zouheir Bitar, Doaa El-Said Bakeer, Ramadan Awad

Turkish Journal of Physics

In the present work, the effect of doping zinc cobalt ferrite by different concentrations of Er3+ on structural, optical, and magnetic properties was studied. Nanosized Zn0.5Co0.5ErxFe2-xO4 (0 ≤ x ≤ 0.2) was synthesized by the coprecipitation method. XRD analysis confirmed the formation of one phase face FCC spinel structure belonging to the Fd3m space group. TEM exhibited that the particle size decreased with the increase of Er3+ content, which is in agreement with XRD results. Two significant absorption bands from FTIR spectra were observed between 400 and 600 cm-1. The band gap energy value obtained from UV-Vis increased with the …

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Effect Of Al Doping On The Magnetic And Elastic Properties Of Fe65 Ni35 Invar Alloys, Asli Çakir Jan 2019

Effect Of Al Doping On The Magnetic And Elastic Properties Of Fe65 Ni35 Invar Alloys, Asli Çakir

Turkish Journal of Physics

Invar alloys have great importance due to their low thermal expansion coefficient. The effect of Al doping on Fe65 Ni35 Invar alloy was investigated by temperature-dependent magnetization and elastic modulus measurements. First, 0.44 at% and 2.24 at% of Al were substituted for Ni. Then X-ray diffraction measurements, Rietveld refinements, and scanning electron microscopy studies were performed to understand the effect of Al-doping on the face-centered cubic structure. The elastic modulus of Fe65 Ni35 and the Al-doped samples were measured in the temperature range 300 ≤ T ≤ 870 K using impulse excitation. The temperature dependence of magnetization and elastic modulus …

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Enhanced Efficiency Of Cds/P3ht Hybrid Solar Cells Via Interfacial Modification, Sali̇h Yilmaz, İsmai̇l Polat, Murat Tomaki̇n, Ahmet Ünverdi̇, Emi̇n Bacaksiz Jan 2019

Enhanced Efficiency Of Cds/P3ht Hybrid Solar Cells Via Interfacial Modification, Sali̇h Yilmaz, İsmai̇l Polat, Murat Tomaki̇n, Ahmet Ünverdi̇, Emi̇n Bacaksiz

Turkish Journal of Physics

The present paper examines the effects of surface modification of CdS with diverse dyes on fabricated CdSbased hybrid solar cells. The X-ray diffraction results showed that CdS thin films had a hexagonal phase with a preferred orientation along the (101) plane. Scanning electron microscopy indicated that the CdS specimen was composed of a granular structure while a P3HT layer was formed from tiny grains. Band gaps of the CdS thin films and the P3HT layer were 2.45 eV and 1.98 eV, respectively. The absorption spectra showed that different dye loading caused an increase in the absorbance of CdS thin films …

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Theoretical Description Of The Two-Color Photoelectron Spectra Process Of Hydrogen: Comparison Between Tdse Calculation And Kroll And Watson Approach, Souhaila Chaddou, Soumia Chqondi, Abdelmalek Taoutioui, Abdelkader Makhoute Jan 2019

Theoretical Description Of The Two-Color Photoelectron Spectra Process Of Hydrogen: Comparison Between Tdse Calculation And Kroll And Watson Approach, Souhaila Chaddou, Soumia Chqondi, Abdelmalek Taoutioui, Abdelkader Makhoute

Turkish Journal of Physics

We present a theoretical study of the main characteristics of two-color photoionization of hydrogen atoms by short strong laser pulses. Our numerical approach is performed by numerically solving the time-dependent Schrödinger equation for a hydrogen atom interacting with Ti:sapphire laser radiation combined with its 15th harmonic. The energy spectra obtained by the direct numerical solution of the Schrödinger equation are compared with those given by the Kroll and Watson perturbative approach. This comparison allows us to check the reliability of the latter approximation.

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Nonlinear Frequency Conversion Of Light Inside A Microcavity, Emre Yüce Jan 2019

Nonlinear Frequency Conversion Of Light Inside A Microcavity, Emre Yüce

Turkish Journal of Physics

Changing the color of light in a small mode volume is essential for applications that require on-chip operation. Microcavities are profound structures given their property to confine light in a small mode volume. Here, I numerically investigate the frequency conversion of light in a microcavity and show that the frequency converted light intensity is distinguished from an open medium such as an optical fiber or a nonlinear crystal. I observe that the frequency converted light intensity increases with increased rate of change of the refractive index of the microcavity. Notably, this study shows that the intensity of the frequency converted …

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Application Of The Fractional Oscillator Model To Describe Damped Vibrations, Sergo Rekhviashvili, Arsen Pskhu, Praveen Agarwal, Shilpi Jain Jan 2019

Application Of The Fractional Oscillator Model To Describe Damped Vibrations, Sergo Rekhviashvili, Arsen Pskhu, Praveen Agarwal, Shilpi Jain

Turkish Journal of Physics

We consider a model of damped vibrations based on fractional differentiation. The model given is completely consistent with the classical model of vibration with viscous damping. We find the relation between the order of fractional differentiation in the equation of motion and Q-factor of an oscillator. The proposed approach seems more appropriate for the physical nature of the described system. The experiment with a vibrating piezoelectric plate, performed as part of the study, showed good agreement with the model and confirmed that the fractional oscillator model can be used to describe strongly damped vibrations.

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Emission Processes Of The Interaction Between The Quantum Well And Donor Delta Layer In Heterostructures For Phemts, Yana Ivanova, George Yakovlev, Vasily Zubkov, Anna Solomnikova Jan 2019

Emission Processes Of The Interaction Between The Quantum Well And Donor Delta Layer In Heterostructures For Phemts, Yana Ivanova, George Yakovlev, Vasily Zubkov, Anna Solomnikova

Turkish Journal of Physics

We present experimental and theoretical investigations of pHEMT heterostructures with AlGaAs/InGaAs/GaAs quantum wells (QWs) and/or a delta-doped layer, which can be used as active regions in transistors operating in the 4-18 GHz frequency range. Using the electrochemical capacitance-voltage setup ECV Pro we, for the first time, experimentally observed a concentration peak from the near-surface delta layer of the pHEMT structure together with a peak of QW enrichment. The capacitance of the electrolyte-semiconductor contact was measured by Agilent LCR-meter, which was connected to the electrochemical cell of ECV Pro through a specially designed relay module. Using numerical simulation of the electronic …

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Effect Of Annealing Temperature On Structural, Electrical, And Uv Sensingcharacteristics Of N-Zno/P-Si Heterojunction Photodiodes, Şenol Kaya Jan 2019

Effect Of Annealing Temperature On Structural, Electrical, And Uv Sensingcharacteristics Of N-Zno/P-Si Heterojunction Photodiodes, Şenol Kaya

Turkish Journal of Physics

The aim of this study is to investigate the influences of annealing temperature on initial device characteristics and their correlations with ultraviolet (UV) radiation sensitivity of n-type zinc oxide/p-silicon (n-ZnO/p-Si) heterojunction photodiodes. Evolutions on the crystalline structure, surface morphology, ideality factor, barrier potential, interface state density, and donor concentration were systematically analyzed during the initial device characterizations before testing the UV sensitivities of the photonic devices. The results demonstrate that the sensitivity of each n-ZnO/p-Si photodiode annealed at various temperatures was linearly correlated with different UV illumination intensities. The devices annealed at 750 ºC and 550 ºC exhibit more sensitive …

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Comparison Of Geometric And Drive-Induced Nonlinearities In Doubly Clamped,Thermoelastic Nanoelectromechanical Systems, Mehmet Seli̇m Hanay Jan 2019

Comparison Of Geometric And Drive-Induced Nonlinearities In Doubly Clamped,Thermoelastic Nanoelectromechanical Systems, Mehmet Seli̇m Hanay

Turkish Journal of Physics

The performance of resonant sensors based on nanoelectromechanical systems depends critically on the maximum amplitude of oscillation reached in the linear regime. The maximum linear amplitude is determined by nonlinear mechanisms that can originate from the material, geometric and transduction mechanism related factors. Here we compare the two competing effects, the geometric and drive-induced nonlinearities, for a commonly used device family, the thermoelastically driven, doubly clamped beams. We find that the geometric nonlinearity dominates for most of the device designs used in the literature, however the drive-induced nonlinearity becomes the determining factor for thicker beams with small electrode lengths.

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Elaboration And Study Of Structural And Optical Properties Of Aubr Nanocrystalsdispersed In Kbr Single Crystals, Hanane Zaioune, Fouzia Zehani, Noureddine Boutaoui, Badis Khennaoui Jan 2019

Elaboration And Study Of Structural And Optical Properties Of Aubr Nanocrystalsdispersed In Kbr Single Crystals, Hanane Zaioune, Fouzia Zehani, Noureddine Boutaoui, Badis Khennaoui

Turkish Journal of Physics

The structural and optical properties of the AuBr nanocrystals embedded in the KBr single crystals grown by the Czochralski method were studied using several techniques. The X-ray diffraction reveals their formation and incorporation. The crystallite average radii calculated from XRD using the Scherrer's formula was found to vary between 19 and 39 nm. The photoluminescence spectra obtained on these same samples present an emission band located at 1.91 eV (650 nm), which can be attributed to the orange luminescence of AuBr nanocrystals. However, the photoluminescence excitation measurements of these nanocrystals exhibit an excitation band located at 3.44 eV (360 nm), …

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Determination Of Fluence Rate Distribution In A Multilayered Skin Tissue Model Byusing Monte Carlo Simulations, Hali̇l Arslan, Bahar Pehli̇vanöz Jan 2019

Determination Of Fluence Rate Distribution In A Multilayered Skin Tissue Model Byusing Monte Carlo Simulations, Hali̇l Arslan, Bahar Pehli̇vanöz

Turkish Journal of Physics

Information on light-tissue interaction is important for clinical applications of lasers. The Monte Carlo technique is one of the commonly used methods to simulate photon propagation and to describe energy absorption in biological tissues. In this study, fluence rate distributions of 633 nm and 830 nm light inside a multilayered skin tissue model have been investigated by using two different simulation software programs: GAMOS tissue optics plug-in and MCML. Results of the plug-in for the fluence rate distributions are in very good agreement with the ones from MCML for both of the wavelengths. This shows that GAMOS tissue optics plug-in …

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The Hirota-Satsuma Coupled Kdv Hierarchy On Noncommutative Phase-Space, Abdelali Saidi, Moulay Brahim Sedra Jan 2019

The Hirota-Satsuma Coupled Kdv Hierarchy On Noncommutative Phase-Space, Abdelali Saidi, Moulay Brahim Sedra

Turkish Journal of Physics

In the present contribution, the Hirota-Satsuma coupled KdV hierarchy on noncommutative phase-space is investigated using the noncommutative extension of Lax pair generating technique. In particular, the explicit representation of its associated Lax pair operators is constructed. It is shown that the obtained results for phase-space noncommutativity case reduce back to the standard commutative case when θ goes to ½.

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The Novel Synthesis And Luminescence Studies Of Cuo And Fe2 O3 Embedded(8-Hydroxyquinoline)Zinc Nanocomposites, Abraham Kutticheril Eapen, Paulose Thomas Jan 2019

The Novel Synthesis And Luminescence Studies Of Cuo And Fe2 O3 Embedded(8-Hydroxyquinoline)Zinc Nanocomposites, Abraham Kutticheril Eapen, Paulose Thomas

Turkish Journal of Physics

The present study investigates the synthesis of novel luminescent polymer nanocomposite through the incorporation of CuO and Fe2 O3 into a C18 H12 N2 O2 Zn host polymer matrix. The observed green electroluminescence behavior originates mainly from the shift in the HOMO-LUMO energy gap of the polymer matrix caused by the inclusion of oxidized metal/oxygen ions from the incorporated metal oxides into the pyridyl and phenyl groups of the host polymer. The existence of oxidized metal/oxygen ionic states in the polymer matrix is successfully confirmed through X-ray photoelectron spectroscopic analysis. The FTIR analysis is utilized to verify the presence of …

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Ab Initio Study Of Li2 Cata2 O7 Compound: Electronic And Optical Properties Forthree Phases, Murat Ayci̇bi̇n Jan 2019

Ab Initio Study Of Li2 Cata2 O7 Compound: Electronic And Optical Properties Forthree Phases, Murat Ayci̇bi̇n

Turkish Journal of Physics

The Li2 CaTa2 O7 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, Li2 CaTa2 O7 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 …

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Tracker-Aided Experiments For The Determination Of Viscosity Coefficients Of Liquidsusing The Communicating Vessels Method With Weighted Regression Analysis, Raden Oktova Jan 2019

Tracker-Aided Experiments For The Determination Of Viscosity Coefficients Of Liquidsusing The Communicating Vessels Method With Weighted Regression Analysis, Raden Oktova

Turkish Journal of Physics

Tracker-aided experiments using communicating vessels have been performed to determine the viscosity coefficients of liquids at room temperature with weighted linear regression analysis. The calculation involves weighted linear regression analysis of -ln[(2z1/z0) - 1] against time, where z1 and z0 are the instantaneous liquid level and the initial liquid level in one of the vessels with the higher initial liquid level, respectively, and a computer-aided χ2 goodness of fit test. Based on the maximum Reynolds number obtained, it is concluded that the liquid flow was laminar, as required by the theory. From the χ2 goodness of fit test it is …

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Reverse-Engineered Scalar Fields In A D-Dimensional Framework, Mustafa Salti, Oktay Aydoğdu, Hi̇lmi̇ Yanar Jan 2019

Reverse-Engineered Scalar Fields In A D-Dimensional Framework, Mustafa Salti, Oktay Aydoğdu, Hi̇lmi̇ Yanar

Turkish Journal of Physics

We are motivated to investigate the dynamics of scalar field dark energy proposals and focus on the reconstruction of a scalar field problem in a D-dimensional framework. With this purpose, we implement a correspondence between the tachyonic scalar field formulation and the additional dimensional cosmological scenario. Such connections help us to redefine the extra dimensional dynamics of the selected scalar field prescription.

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Pseudoscalar Higgs Boson Pair Production At A Photon-Photon Collision In Thetwo Higgs Doublet Model, Mehmet Demi̇rci̇ Jan 2019

Pseudoscalar Higgs Boson Pair Production At A Photon-Photon Collision In Thetwo Higgs Doublet Model, Mehmet Demi̇rci̇

Turkish Journal of Physics

In this study, the direct pair production of the pseudoscalar Higgs boson at a γγ collision is analyzed in the context of the two Higgs doublet model (THDM), taking into account the complete one-loop contributions. In order to illustrate the effect of the new physics, four benchmark point scenarios, which are consistent with theoretical and current experimental constraints, are chosen in the type-I THDM with an exact alignment limit. The effect of individual contributions from each type of one-loop diagram on the total cross-section is examined in detail. The dependence of the cross-section on the center-of-mass energy is also presented …

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First Photometric Investigation Of Some Asas Binary Systems, Burak Ulaş Jan 2019

First Photometric Investigation Of Some Asas Binary Systems, Burak Ulaş

Turkish Journal of Physics

We present the first light curve solutions of the four binary systems observed and catalogued by the All Sky Automated Survey (ASAS) program. The light curves are analyzed by using PHOEBE software, which is based on the Wilson?Devinney method. The light curve parameters are derived and the estimated physical parameters are calculated from the result of the analyses. We compare our targets to well-known binaries of similar type on the Hertzsprung-Russell diagram and mass-radius plane. The evolutionary states of the components are also discussed.

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Topography Of Electrospun Nanofibers And Its Influence On (Pot/Ps)/Si Hybridsolar Cell Parameters, Tariq Jaffar Alwan Jan 2019

Topography Of Electrospun Nanofibers And Its Influence On (Pot/Ps)/Si Hybridsolar Cell Parameters, Tariq Jaffar Alwan

Turkish Journal of Physics

Alignment nanofibers of poly(o-toluidine)/polystyrene (POT/PS) were prepared by using an electrospinning method at different applied voltages (Vappl.) of 10, 15, and 20 kV. The effect of the applied voltage on the morphology and electrical properties of POT/PS nanofibers was studied. Morphology and diameters of the nanofibers were investigated via atomic force microscopy. (POT/PS)/Si hybrid solar cells were fabricated through the deposition of POT/PS nanofibers on Si wafers using the electrospinning technique. The current-voltage measurements of the device under dark conditions exhibited asymmetrical and rectifying behavior for the Al/(POT/PS)/Si/Al junction, thereby confirming the formation of diodes. Diode parameters, such as ideality …

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Second-Order Gauge-Invariant Perturbation Theory And Conserved Charges Incosmological Einstein Gravity, Emel Altaş Ki̇raci Jan 2019

Second-Order Gauge-Invariant Perturbation Theory And Conserved Charges Incosmological Einstein Gravity, Emel Altaş Ki̇raci

Turkish Journal of Physics

Recently a new approach in constructing the conserved charges in cosmological Einstein gravity was given. In this new formulation, instead of using the explicit form of the field equations, a covariantly conserved rank-four tensor was used. In the resulting charge expression, instead of the first derivative of the metric perturbation, the linearized Riemann tensor appears along with the derivative of the background Killing vector fields. Here we give a detailed analysis of the first-order and the second-order perturbation theory in a gauge-invariant form in cosmological Einstein gravity. The linearized Einstein tensor is gauge-invariant at the first order but it is …

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Ab Initio Atomistic Thermodynamics Modeling Of Adsorption Of Oxygen On Goldand Gold-Silver Surfaces, Mehmet Gökhan Şensoy Jan 2019

Ab Initio Atomistic Thermodynamics Modeling Of Adsorption Of Oxygen On Goldand Gold-Silver Surfaces, Mehmet Gökhan Şensoy

Turkish Journal of Physics

A theoretical study of oxygen adsorption on gold and gold-silver surfaces by means of density functional theory (DFT) calculations with an atomistic thermodynamic model is performed. The (111) and (211) facets of gold and gold-silver alloy surfaces are considered, and their stabilization is discussed upon adsorption of oxygen depending on O and Ag coverage. The details of how the DFT-based atomistic thermodynamic model can apply to the transition metal surface are also presented in this work.

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Two-Dimensional Ti2c Monolayer (Mxene): Surface Functionalization, Inducedmetal, Semiconductor Transition, Berna Akgenc Jan 2019

Two-Dimensional Ti2c Monolayer (Mxene): Surface Functionalization, Inducedmetal, Semiconductor Transition, Berna Akgenc

Turkish Journal of Physics

Recently, two-dimensional (2D) transition metal carbides and nitrides known as MXenes, have gained a lot of attention because of their tunable electronic and magnetic properties depending on surface functionalization. In the present work, the structural, electronic, and magnetic properties of both T and H phases of bare Ti2C and fully surface terminated Ti2 CT2 (T = -F, = O, -OH) are calculated using a set of first principles calculations. The ground state structures of Ti2 CT2 are computed in two and four different configurations for both H and T phases, respectively. We demonstrate that while H phase of Ti2C exhibits …

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