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Full-Text Articles in Physical Sciences and Mathematics

Some Results On T-Noncosingular Modules, Rachid Tribak Jan 2014

Some Results On T-Noncosingular Modules, Rachid Tribak

Turkish Journal of Mathematics

The notion of T-noncosingularity of a module has been introduced and studied recently. In this article, a number of new results of this property are provided. It is shown that over a commutative semilocal ring R such that Jac(R) is a nil ideal, every T-noncosingular module is semisimple. We prove that for a perfect ring R, the class of T-noncosingular modules is closed under direct sums if and only if R is a primary decomposable ring. Finitely generated T-noncosingular modules over commutative rings are shown to be precisely those having zero Jacobson radical. We also show that for a simple …


A Class Of Uniquely (Strongly) Clean Rings, Orhan Gürgün, Ayşe Çi̇ğdem Özcan Jan 2014

A Class Of Uniquely (Strongly) Clean Rings, Orhan Gürgün, Ayşe Çi̇ğdem Özcan

Turkish Journal of Mathematics

In this paper we call a ring R \delta_r-clean if every element is the sum of an idempotent and an element in \delta(R_R) where \delta(R_R) is the intersection of all essential maximal right ideals of R. If this representation is unique (and the elements commute) for every element we call the ring uniquely (strongly) \delta_r-clean. Various basic characterizations and properties of these rings are proved, and many extensions are investigated and many examples are given. In particular, we see that the class of \delta_r-clean rings lies between the class of uniquely clean rings and the class of exchange rings, and …


On The Structure Of Some Modules Over Generalized Soluble Groups, Leonid Andreevich Kurdachenko, Igor Yakov Subbotin, Vasiliy Anatolievich Chupordya Jan 2014

On The Structure Of Some Modules Over Generalized Soluble Groups, Leonid Andreevich Kurdachenko, Igor Yakov Subbotin, Vasiliy Anatolievich Chupordya

Turkish Journal of Mathematics

Let R be a ring and G a group. An R-module A is said to be Artinian-by-(finite rank) if Tor_R(A) is Artinian and A/ Tor_R(A) has finite R-rank. We study a module A over a group ring RG such that A/C_A(H) is Artinian-by-(finite rank) (as an R-module) for every proper subgroup H.


On 2 Nonsplit Extension Groups Associated With Hs And Hs:2, Jamshid Moori, Thekiso Seretlo Jan 2014

On 2 Nonsplit Extension Groups Associated With Hs And Hs:2, Jamshid Moori, Thekiso Seretlo

Turkish Journal of Mathematics

The group HS:2 is the full automorphism group of the Higman--Sims group HS. The groups 2^{4.}S_6 and 2^{5.}S_6 are maximal subgroups of HS and HS:2, respectively. The group 2^{4.}S_6 is of order 11520 and 2^{5.}S_6 is of order 23040 and each of them is of index 3 850 in HS and HS:2, respectively. The aim of this paper is to first construct \overline{G} = 2^{5.}S_6 as a group of the form 2^{4.}S_6.2 (that is, \overline{G} = G_1.2) and then compute the character tables of these 2 nonsplit extension groups by using the method of Fischer--Clifford theory. We will show that …


On Finsler Metrics With Vanishing S-Curvature, Akbar Tayebi, Hassan Sadeghi, Esmaeil Peyghan Jan 2014

On Finsler Metrics With Vanishing S-Curvature, Akbar Tayebi, Hassan Sadeghi, Esmaeil Peyghan

Turkish Journal of Mathematics

In this paper, we consider Finsler metrics defined by a Riemannian metric and a 1-form on a manifold. We study these metrics with vanishing S-curvature. We find some conditions under which such a Finsler metric is Berwaldian or locally Minkowskian.


Conformally Parallel Spin(7) Structures On Solvmanifolds, Selman Uğuz Jan 2014

Conformally Parallel Spin(7) Structures On Solvmanifolds, Selman Uğuz

Turkish Journal of Mathematics

In this paper we review the Spin(7) geometry in relation to solvmanifolds. Starting from a 7-dimensional nilpotent Lie group N endowed with an invariant G_2 structure, we present an example of a homogeneous conformally parallel Spin(7) metric on an associated solvmanifold. It is thought that this paper could lead to very interesting and exciting areas of research and new results in the direction of (locally conformally) parallel Spin(7) structures.


Geometry Of Almost Cliffordian Manifolds: Classes Of Subordinated Connections, Jaroslav Hrdina, Petr Vasik Jan 2014

Geometry Of Almost Cliffordian Manifolds: Classes Of Subordinated Connections, Jaroslav Hrdina, Petr Vasik

Turkish Journal of Mathematics

An almost Clifford and an almost Cliffordian manifold is a G--structure based on the definition of Clifford algebras. An almost Clifford manifold based on O:= Cl (s,t) is given by a reduction of the structure group GL(km, R) to GL(m, O), where k=2^{s+t} and m \in N. An almost Cliffordian manifold is given by a reduction of the structure group to GL(m, O) GL(1, O). We prove that an almost Clifford manifold based on O is such that there exists a unique subordinated connection, while the case of an almost Cliffordian manifold based on O is more rich. A class …


The Results Of The First Photonuclear Reaction Performed In Turkey: The Zinc Example, İsmai̇l Boztosun, Haris Dapo, Süleyman Fati̇h Özmen, Yi̇ği̇t Çeçen, Mesut Karakoç, Abdullah Çoban, Alp Cesur, Tanfer Caner, Edi̇p Bayram, Gi̇zem Büşra Keller, Beyza Küçük, Abdullah Güvendi̇, Melek Derman, Deni̇z Kaya Jan 2014

The Results Of The First Photonuclear Reaction Performed In Turkey: The Zinc Example, İsmai̇l Boztosun, Haris Dapo, Süleyman Fati̇h Özmen, Yi̇ği̇t Çeçen, Mesut Karakoç, Abdullah Çoban, Alp Cesur, Tanfer Caner, Edi̇p Bayram, Gi̇zem Büşra Keller, Beyza Küçük, Abdullah Güvendi̇, Melek Derman, Deni̇z Kaya

Turkish Journal of Physics

We have investigated the decays of several zinc isotopes produced by photonuclear reactions, which were induced by bremsstrahlung photon beams from a clinical e-linac. A photon beam of 18 MeV endpoint energy was directed at a target consisting of primarily zinc isotopes in their natural abundances. Subsequently, the induced decays of unstable zinc isotopes were measured with an HPGe detector twice, once shortly after irradiation and once on the following day. Decays of Zn-63, Zn-65, Zn-69m, and Cu-67 were measured and fitted. In addition, the gamma energy levels of the daughters of these decays were measured with good accuracy. All …


Theoretical Investigations Of Pt_3x (X = Al, Sc, Hf, Zr) Ground State, Adewumi Isaac Popoola, Lesley Heath Chown, Lesley Alison Cornish Jan 2014

Theoretical Investigations Of Pt_3x (X = Al, Sc, Hf, Zr) Ground State, Adewumi Isaac Popoola, Lesley Heath Chown, Lesley Alison Cornish

Turkish Journal of Physics

The electronic structure of Pt_3X compounds showed that Pt_3Hf and Pt_3Zr were more stable for the D0_{24} structure, rather than L1_2. The compound Pt_3Al was predicted to be the hardest and most ductile, but not with the L1_2 structure at ground state. The density of states showed that Pt_3Hf, Pt_3Zr, and Pt_3Al can be stabilized to the L1_2 phase with suitable element addition. All calculations were done within the density functional theory framework.


Thermodynamic Properties Of A Rotating Bose-Einstein Condensation In A Deep Optical Lattice, Hend A. Abdel-Gany, Ali Y. Ellithi, Abdelhamid A. Galal, Ahmed Hassan Jan 2014

Thermodynamic Properties Of A Rotating Bose-Einstein Condensation In A Deep Optical Lattice, Hend A. Abdel-Gany, Ali Y. Ellithi, Abdelhamid A. Galal, Ahmed Hassan

Turkish Journal of Physics

In this paper, we suggest a conventional semiclassical approximation to calculate several thermodynamic quantities of a rotating Bose-Einstein condensation in a deep optical lattice. Expressions for the condensation fraction, critical temperature, and heat capacity are derived analytically. These expressions are obtained by considering the standard harmonic approximation of the deep optical lattice potential. The suggested approach is able to include the the finite size and the positive chemical potential effects simultaneously. The advantage of our suggested approach is in its simplicity, in comparison to the quantum-mechanical calculations (Bose-Hubbard model). Moreover, its generality allows the treatment of a finite temperature regime


Transmission Of A Broadband Light Through A Fiber Optic Loop: Effect Of Nonlinear Refractive Index, Erkin Zakhidov, Abdumutallib Kokhkharov, Farrukh Mirtagjiev, Sherzod Nematov, Ilkhom Todjiboev, Olga Trunilina Jan 2014

Transmission Of A Broadband Light Through A Fiber Optic Loop: Effect Of Nonlinear Refractive Index, Erkin Zakhidov, Abdumutallib Kokhkharov, Farrukh Mirtagjiev, Sherzod Nematov, Ilkhom Todjiboev, Olga Trunilina

Turkish Journal of Physics

The results of studies of broadband light transmission through a fiber loop and a double loop under the effect of nonlinear refractive index are presented in this paper. Fiber loop and double loop transmission/reflection vs. a coupler splitting ratio at various powers of the light with a spectral width of approximately 35 nm are studied and high efficient nonlinear light switching is demonstrated. It is shown that a double loop formed by consecutive connecting 2 fiber loops allows us to exclude the strong spectral dependence of light transmission/reflection and to distribute input light equally between them. Such all-fiber devices can …


A Model Of The Multijunction Ac Josephson Effect In A Superconductor, Mohammed Rafiqul Islam, Habibur Rahman Jan 2014

A Model Of The Multijunction Ac Josephson Effect In A Superconductor, Mohammed Rafiqul Islam, Habibur Rahman

Turkish Journal of Physics

We present a model of the multijunction ac Josephson effect in a superconductor. Josephson predicted that at a finite applied voltage (V_o) an alternating supercurrent of frequency \omega_J =2eV_o/\hslash flows between 2 superconductors separated by an insulating layer, called the ac Josephson effect. Adding 2 or more Josephson junctions (so-called multijunction) with an applied voltage, we have shown that the resultant current (which is equivalent to the vector sum of the currents in each junction) has the same frequency as the single Josephson junction. The amplitude of the resultant current for the multijunction is increased with the increasing number of …


Analytical Solution Of The Klein-Gordon Equation Under The Coulomb-Like Scalar Plus Vector Potential With The Laplace Transforms Approach, Ebrahim Momtazi, Ali Akbar Rajabi, Bentol Hoda Yazarloo, Hassan Hassanabadi Jan 2014

Analytical Solution Of The Klein-Gordon Equation Under The Coulomb-Like Scalar Plus Vector Potential With The Laplace Transforms Approach, Ebrahim Momtazi, Ali Akbar Rajabi, Bentol Hoda Yazarloo, Hassan Hassanabadi

Turkish Journal of Physics

In this paper, analytical solution of the Klein-Gordon equation with Coulomb-like scalar plus vector potentials is obtained exactly. We considered the Laplace transform approach in our calculation. The exact bound state energy eigenvalues and the corresponding eigenfunctions are reported for various values of the quantum numbers n and l.


Aldimine Derivatives As Photosensitizers For Dye-Sensitized Solar Cells, Amal Y. Batniji, Rami Morjan, Monzir S. Abdel-Latif, Taher M. El-Agez, Sofyan A. Taya, Hatem S. El-Ghamri Jan 2014

Aldimine Derivatives As Photosensitizers For Dye-Sensitized Solar Cells, Amal Y. Batniji, Rami Morjan, Monzir S. Abdel-Latif, Taher M. El-Agez, Sofyan A. Taya, Hatem S. El-Ghamri

Turkish Journal of Physics

Five aldimine derivatives were prepared by condensation of the appropriate amine with salicylaldehyde (m1-m4) and 4-aminobenzoic acid with 2-thiophene carboxaldehyde (m5). A molar ratio of 1:1 was used and the mixture was refluxed in ethanol for 2 h to obtain the corresponding aldimine derivative. These derivatives were used as photosensitizers for dye-sensitized solar cells (DSSCs). The best performance was obtained for the DSSC sensitized with 2-(2-hydroxybenzylideneamino)benzoic acid, for which a short-circuit current of 2.86 mA/cm^2, an open-circuit voltage of 0.562 V, and an efficiency of 0.575% were obtained.


Influence Of Composition On The Structure And Optoelectronic Properties Of Pb_Xin_{25-X}Se_{75} Thin Films, Hesham Azmi Elmeleegi, Zeinab El Sayed El Mandouh, Ahmed Abdel Moez Jan 2014

Influence Of Composition On The Structure And Optoelectronic Properties Of Pb_Xin_{25-X}Se_{75} Thin Films, Hesham Azmi Elmeleegi, Zeinab El Sayed El Mandouh, Ahmed Abdel Moez

Turkish Journal of Physics

Pb_xIn_{25-x}Se_{75} thin films with 2 compositions were prepared by thermal evaporation. The surface topography of these films was studied by transmission electron microscope. The optical reflectance and transmittance were studied in order to determine the optical parameters such as optical energy gap, refractive index, extinction coefficient, dielectric loss, and dielectric tangent loss for these films. A single oscillator theory equation was applied for these films in order to determine both dispersion energy and oscillating energy, and the ratio of free carrier concentration/effective mass (N/m*) was determined optically. It was found that change in the composition of these films affects strongly …


Representation Of Electromagnetic And Gravitoelectromagnetic Poynting Theorems In Higher Dimensions, Mustafa Emre Kansu, Murat Tanişli, Süleyman Demi̇r Jan 2014

Representation Of Electromagnetic And Gravitoelectromagnetic Poynting Theorems In Higher Dimensions, Mustafa Emre Kansu, Murat Tanişli, Süleyman Demi̇r

Turkish Journal of Physics

This study investigates whether the electromagnetic and gravitoelectromagnetic energy conservation equations are obtained together by using octonion algebra or not. Maxwell and Maxwell-like equations for linear gravity with magnetic monopole terms are used in the SI unit system. A new complex octonionic field term is suggested for the first time. The complex octonionic source equation is then obtained. Finally, Poynting theorems for both electromagnetism and gravitoelectromagnetism are defined for the first time by using higher dimensional algebra.


Perturbative Approach To The Spin-Flavor Precession Of Majorana-Type Solar Neutrinos, Deni̇z Yilmaz Jan 2014

Perturbative Approach To The Spin-Flavor Precession Of Majorana-Type Solar Neutrinos, Deni̇z Yilmaz

Turkish Journal of Physics

Spin-flavor precession (SFP) of Majorana-type solar neutrinos is investigated in the case of 2 generations. The evolution equation in the SFP framework is solved by using the perturbative method, in which mu B is accepted to be small. The approximate analytical formula including SFP effect is provided.


Magnetized Kantowski-Sachs Bulk Viscous String Cosmological Models With Decaying Vacuum Energy Density Lambda (T), Kanika Das, Nawsad Ali Jan 2014

Magnetized Kantowski-Sachs Bulk Viscous String Cosmological Models With Decaying Vacuum Energy Density Lambda (T), Kanika Das, Nawsad Ali

Turkish Journal of Physics

In this paper, we deal with bulk viscous magnetized Kantowski-Sachs string cosmological models in the presence of time variable cosmological term Lambda . To obtain a deterministic model, we assume the conditions sigma infty theta and zeta theta = constant, where sigma is the shear, theta the expansion in the model, and zeta the coefficient of bulk viscosity. The value of cosmological constant for the models is found to be small and positive, which is supported by the results from recent observations (SN 1a). The behavior of the model in the presence and absence of magnetic fields together with physical …


Analogue And Digital Analysis Of The Effects Of Some Parameters In Determination Of The Best Experimental Energy Resolution, Eli̇f Ebru Ermi̇ş, Gözde Tektaş, Ercan Pi̇li̇çer, Cüneyt Çeli̇ktaş, Jiri Pechousek Jan 2014

Analogue And Digital Analysis Of The Effects Of Some Parameters In Determination Of The Best Experimental Energy Resolution, Eli̇f Ebru Ermi̇ş, Gözde Tektaş, Ercan Pi̇li̇çer, Cüneyt Çeli̇ktaş, Jiri Pechousek

Turkish Journal of Physics

The gamma-ray energy spectrum of ^{137}Cs was obtained according to different parameters such as preamplifier capacitance, the amplifier's coarse gain level, power supply voltage for the detector, and source-to-detector distance. This investigation was performed with both analogue and digital methods. In order to examine the effects of these parameters on energy resolution, a NaI(Tl) inorganic scintillation detector was used. In addition, the gamma energy spectrum of the radioisotope was obtained by means of FLUKA, which is one of the Monte Carlo simulation programmes. Energy resolution of the detector by these 3 methods was calculated. These resolution values were compared with …


Double Pulse Generation In A Highly Nonlinear Gaas Optical Waveguide, Jian Wei Wu Jan 2014

Double Pulse Generation In A Highly Nonlinear Gaas Optical Waveguide, Jian Wei Wu

Turkish Journal of Physics

This paper presents a simulation and investigation about the nonlinear interplay between an optical pulse and GaAs waveguide. The results obtained show that the nonlinear processes including self-phase modulation, 2-photon absorption, and free carrier related effects will have significant influences on the temporal shape and frequency spectrum of a propagating pulse in the GaAs waveguide with the result that 2-photon absorption can extend the pulse duration that can be again compressed by the free carrier absorption. The outcome spectrum is also asymmetrical due to the free carrier related effects, which takes on a complicated oscillation structure resulting from the interference. …


Annealing Effect On Zinc Nanoferrite Particles Synthesized By Spray Pyrolysis Of Polymer Precursor, Jessyamma Kurian, Subin John, Jacob Mathew Jan 2014

Annealing Effect On Zinc Nanoferrite Particles Synthesized By Spray Pyrolysis Of Polymer Precursor, Jessyamma Kurian, Subin John, Jacob Mathew

Turkish Journal of Physics

Nanosized zinc ferrite particles, prepared by spray pyrolysis method, were investigated by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy, Fe^{57} Mossbauer spectroscopy, and vibrating sample magnetometer. The cubic crystalline phases were identified in all samples. The lattice parameter (a = 8.446 Å) and the average particle size of all the samples were determined. The particle sizes increased as the annealing temperature increased from 250 °C to 550 °C. The variation in structural parameters and particle size estimated from X-ray diffraction patterns of heat-treated samples suggested that the synthesized sample was in a `metastable' state or a compositionally constrained state. …


Iii-Nitride Quantum Dots In Nanowires: Growth, Structural, And Optical Properties, Bruno Daudin Jan 2014

Iii-Nitride Quantum Dots In Nanowires: Growth, Structural, And Optical Properties, Bruno Daudin

Turkish Journal of Physics

Nanowires (NWs) have emerged as a platform to build complex, self-assembled, defect-free nanostructures. In particular, the growth of single islands/disks of various III-nitride combinations (InGaN in GaN, GaN in AlN, AlGaN in AlN) are possible in NW heterostructures, extending the field of experimental quantum dot exploration. Specific to NWs, the possibility to disperse them paves the way to probe and investigate only a single wire/dot. In the present article, the growth of GaN disks/islands and InGaN islands as well as their optical properties at the nanometer scale will be reviewed. Besides the intentional growth of QD-in NW heterostructures, special attention …


A Study On Si And P Doped H-Bn Sheets: Dft Calculations, Hati̇ce Kökten, Şaki̇r Erkoç Jan 2014

A Study On Si And P Doped H-Bn Sheets: Dft Calculations, Hati̇ce Kökten, Şaki̇r Erkoç

Turkish Journal of Physics

Structural properties and energetics of silicon and phosphorus doped hexagonal boron nitride sheets were investigated by performing density functional theory calculations. The dopant atoms were substituted in a neutral charge state at either the B or the N site in the system as an impurity. All the systems under consideration were fully optimized. A systematic study was performed to see the effect of cell size on the calculated quantities, such as bond length, charge transfer, and defect formation energies. It was found that both silicon and phosphorus atom substitutions cause the bond lengths to increase with respect to the pristine …


Self-Assembled Nanocrystalline Zno Thin Film Transistor Performance Optimization For High Speed Applications, Burhan Bayraktaroglu, Kevin Leedy Jan 2014

Self-Assembled Nanocrystalline Zno Thin Film Transistor Performance Optimization For High Speed Applications, Burhan Bayraktaroglu, Kevin Leedy

Turkish Journal of Physics

ZnO nanocrystals grown at relatively low temperatures using various vacuum deposition techniques can yield semiconducting thin films of self-assembled nanocolumns 20-50 nm in diameter. Such films are suitable for the fabrication of high speed and transparent thin film transistors (TFTs). Unlike amorphous TFTs, the performance of ZnO transistors depends both on the crystal quality of nanocrystals and the electrical properties of boundary layers between them. We investigated the use of radio frequency sputtering, atomic layer deposition, and pulsed laser deposition techniques to fabricate self-assembled nanocrystalline thin films and determined the influence of deposition conditions on the performance of transistors. Device …


Gan Nanostructuring For The Fabrication Of Thin Membranes And Emerging Applications, Ion Tiginyanu, Veaceslav Ursaki Jan 2014

Gan Nanostructuring For The Fabrication Of Thin Membranes And Emerging Applications, Ion Tiginyanu, Veaceslav Ursaki

Turkish Journal of Physics

We present a review of technological methods developed in recent years for the purpose of gallium nitride nanostructuring, with the main focus on fabrication of thin GaN membranes. In particular, we report on traditional methods of wet etching undercutting for membrane manufacturing, technologies applied for the fabrication of photonic crystal structures based on GaN nanomembranes, double side processing, and surface charge lithography. Prospects of membrane applications in photonic devices, sensors, and microoptoelectromechanical and nanoelectromechanical systems are discussed, taking into account the advantageous piezoelectric, optical, and mechanical properties of GaN and related III-V nitride materials.


Optical Properties Of Zno/(Zn, Mg)O Quantum Wells, Thierry Bretagnon Jan 2014

Optical Properties Of Zno/(Zn, Mg)O Quantum Wells, Thierry Bretagnon

Turkish Journal of Physics

This paper reviews the optical properties of ZnO/(Zn, Mg)O single quantum wells grown by molecular beam epitaxy. Both heteroepitaxial quantum well growth along the polar c-direction and homoepitaxial quantum well growth on the nonpolar M plane cases are considered. The optical properties of these quantum wells are investigated by using reflectance, continuous wave photoluminescence, and time-resolved photoluminescence spectroscopies. The quantum-confined Stark effect dominates the properties of the excitons for polar quantum wells. The magnitude of the internal electric field that is induced by both spontaneous and piezoelectric polarizations is determined by comparing the experimental results with a variational calculation of …


Zno-Based Nanostructures For Diluted Magnetic Semiconductor, Millaty Mustaqima, Chunli Liu Jan 2014

Zno-Based Nanostructures For Diluted Magnetic Semiconductor, Millaty Mustaqima, Chunli Liu

Turkish Journal of Physics

Since the prediction by Dietl et al. in the year 2000, extensive research activities have been focused on the ZnO-based diluted magnetic materials (DMSs). Earlier works were mainly performed using bulk or thin film materials with transition-metal doping, and diverse magnetic properties including ferromagnetism, paramagnetism, and diamagnetism have been reported. Identifying the dominant mechanism of the ferromagnetic ordering and realizing reproducible ferromagnetism above room temperature have been the main research issues, but a consensus is still lacking even today. Recently, reports on ZnO nanostructures with ferromagnetic behavior have been growing due to the novel properties brought about by the high …


The Influence Of Tio_2 Nanostructure Properties On The Performance Of Tio_2-Based Anodes In Lithium Ion Battery Applications, Xiang Liu, Qian Sun, Fangzhou Liu, Aleksandra B. Djurisic, Alan Man Ching Ng, Maohai Xie, Tom Wood, Juan Antonio Zapien, Changzhong Liao, Kaiming Shih Jan 2014

The Influence Of Tio_2 Nanostructure Properties On The Performance Of Tio_2-Based Anodes In Lithium Ion Battery Applications, Xiang Liu, Qian Sun, Fangzhou Liu, Aleksandra B. Djurisic, Alan Man Ching Ng, Maohai Xie, Tom Wood, Juan Antonio Zapien, Changzhong Liao, Kaiming Shih

Turkish Journal of Physics

We investigated the properties of 7 different titanium dioxide nanostructures with different crystal structures (3 anatase, 2 rutile, and 2 mixed anatase--rutile phase). Nanoparticle samples and mesoporous sphere samples were investigated. Even for the same crystal structure, significant variations in performance were observed for anatase titania samples, while 2 rutile samples exhibited similar performance inferior to anatase-based anodes. Mixed-phase samples also exhibited lower specific capacity compared to the best performing anatase samples, and in this case a significant difference in performance was observed between nanoparticles and mesoporous spheres.


Two-Dimensional Mos_2 As A New Material For Electronic Devices, Natalia Izyumskaya, Denis O. Demchenko, Vitaliy Avrutin, Ümi̇t Özgür, Hadis Morkoç Jan 2014

Two-Dimensional Mos_2 As A New Material For Electronic Devices, Natalia Izyumskaya, Denis O. Demchenko, Vitaliy Avrutin, Ümi̇t Özgür, Hadis Morkoç

Turkish Journal of Physics

We overview fundamental properties, preparation techniques, and potential device applications of single- and few-monolayer-thick molybdenum disulfide MoS_2 belonging to a new emerging class of materials: 2-dimensional semiconductors. To a large extent, the interest in the 2-dimensional materials is fueled by the quest for alternatives to graphene, which is hardly suitable for electronic devices because of the lack of a band gap. A unique combination of physical properties, including flexibility, high electron mobility, and optical transparency combined with a large band gap tunable from indirect 1.2 eV for bulk to direct 1.9 eV for a monolayer, make MoS_2 attractive for a …


Recent Advances In Organic Field Effect Transistors, Özge Abanoz, Christos Dimitrakopoulos Jan 2014

Recent Advances In Organic Field Effect Transistors, Özge Abanoz, Christos Dimitrakopoulos

Turkish Journal of Physics

We review the progress in the performance of organic field effect transistors that has been reported in the last 30 years, with a major emphasis on the last 10 years. We focus on the best performing organic semiconductors, and elucidate the underlying relations between the chemical and physical structures of the materials in the solid state and their electronic properties.