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Articles 1 - 30 of 51
Full-Text Articles in Physical Sciences and Mathematics
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
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
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.
Evidence That Photons Have Extension In Space, Randy Wayne
Evidence That Photons Have Extension In Space, Randy Wayne
Turkish Journal of Physics
Satyendra Nath Bose realized that there was a logical inconsistency in the derivation of Planck's radiation law since the derivation used to obtain the temperature-independent prefactor in the blackbody radiation law had been based in part on classical wave hypotheses, such as the number of degrees of freedom of the ether. Bose worked out a strictly quantum derivation by combining the quantum hypothesis with statistical mechanics to determine the number of states of each mode that would occupy a 6-dimensional phase space. Here I use the model of an extended photon to show that the temperature-independent prefactor of Planck's radiation …
Deriving The Snel-Descartes Law For A Single Photon, Randy Wayne
Deriving The Snel-Descartes Law For A Single Photon, Randy Wayne
Turkish Journal of Physics
The laws of reflection and refraction are typically derived using a dispersion relation that assumes that the angular frequency stays the same across a vacuum--dielectric interface and that the angular wave number increases. At the single photon level, this means that the total energy of the photon is conserved but the linear momentum is not. Here I derive the laws of reflection and refraction for a single photon using a dispersion relation that is consistent with the conservation of both total energy and linear momentum. To ensure that both conservation laws are upheld, the optical path length must be considered …
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
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
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
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
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
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.
Effect Of Gain Saturation On The Nonlinear Dynamical Behavior Of Optically Injected Semiconductor Lasers, Furat Ahmad Al-Saymari, Imad Al-Deen Hussein Al-Saidi, May Jassim Ashoor
Effect Of Gain Saturation On The Nonlinear Dynamical Behavior Of Optically Injected Semiconductor Lasers, Furat Ahmad Al-Saymari, Imad Al-Deen Hussein Al-Saidi, May Jassim Ashoor
Turkish Journal of Physics
We studied numerically the dynamics and bifurcations route to chaos of an optically injected semiconductor laser. The sequence of bifurcations mainly followed the period-doubling scenario. Observations of different kinds of injected semiconductor laser dynamical behaviors including stable state, periodic oscillation state, quasi-periodic oscillation state, co-existence of periodic and chaotic states, and period-3 and period-6 oscillation states are reported. The existence of isolated branches created from a sudden jump in the dynamics of the semiconductor laser was also observed in the bifurcation diagram. In order to draw a detailed picture for the dynamical behavior of the semiconductor laser, we constructed color …
Xrd, Xps, And Optical Characterizations Of Al-Doped Zno Film Grown On Gaas Substrate, Ebru Şenadim Tüzemen, Hülya Şahi̇n, Kamuran Kara, Sezai̇ Elagöz, Ramazan Esen
Xrd, Xps, And Optical Characterizations Of Al-Doped Zno Film Grown On Gaas Substrate, Ebru Şenadim Tüzemen, Hülya Şahi̇n, Kamuran Kara, Sezai̇ Elagöz, Ramazan Esen
Turkish Journal of Physics
A ZnO:Al (10%) thin film was prepared on GaAs(100) substrate by using a pulsed filtered cathodic vacuum arc deposition (PFCVAD) system. The ZnO:Al thin film was thermally annealed for 1 h at 2 different temperatures in air. The film structure was investigated as a function of annealing temperature by X-ray diffraction (XRD). ZnO:Al film annealed at 500 °C by PFCVAD method resulted in an amorphous film. However, after annealing ZnO:Al film at 600 °C, it showed (100) and (002) peaks at around 32° and 34°, respectively. The chemical state of ZnO:Al (AZO) film on GaAs substrate was investigated by using …
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
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
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.
Fast Numerical Algorithm For A High-Precision 6d Electromagnetic Positioning Navigation System, Qian Xiang, Shiqing Wang, Haifeng Liu
Fast Numerical Algorithm For A High-Precision 6d Electromagnetic Positioning Navigation System, Qian Xiang, Shiqing Wang, Haifeng Liu
Turkish Journal of Physics
A fast numerical algorithm is proposed for the 6 degrees of freedom electromagnetic navigation system, which can be used to improve surgical operations guided by medical images. Both the rotation transformation technique and optimization technique are adopted in the algorithm. The results from simulations show that the calculating time is improved greatly under the required precision in the surgery. A navigation system based on the algorithm can make the medical device's dimensions miniaturized and the structure simplified and portable. The performance and application scope of the electromagnetic positioning navigation system can be improved.
Perturbative Approach To The Spin-Flavor Precession Of Majorana-Type Solar Neutrinos, Deni̇z Yilmaz
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
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
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
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. …
Incidence Angle And Spectral Effects On Vertical Junction Silicon Solar Cell Capacitance, Moustapha Sane, Gökhan Şahi̇n, Fabe Idrissa Barro, Amadou Seidou Maiga
Incidence Angle And Spectral Effects On Vertical Junction Silicon Solar Cell Capacitance, Moustapha Sane, Gökhan Şahi̇n, Fabe Idrissa Barro, Amadou Seidou Maiga
Turkish Journal of Physics
The aim of this work is to present a theoretical study of a vertical junction silicon solar cell under monochromatic illumination. By solving the continuity equation and using a one-dimensional model in frequency modulation, we derive the analytical expressions of both excess minority carrier density and photovoltage. Based on these expressions, the solar cell capacitance was calculated; we then exhibited the effects of both illumination wavelength and incidence angle on the solar cell capacitance.
Annealing Effect On Zinc Nanoferrite Particles Synthesized By Spray Pyrolysis Of Polymer Precursor, Jessyamma Kurian, Subin John, Jacob Mathew
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. …
Annealing Effects Of Zno Thin Films On P-Si(100) Substrate Deposited By Pfcvad, Kamuran Kara, Ebru Şenadim Tüzemen, Ramazan Esen
Annealing Effects Of Zno Thin Films On P-Si(100) Substrate Deposited By Pfcvad, Kamuran Kara, Ebru Şenadim Tüzemen, Ramazan Esen
Turkish Journal of Physics
In this study, ZnO films were prepared on p-Si substrates using the pulsed filtered cathodic vacuum arc deposition (PFCVAD) method. We report the effect of annealing temperature on structural and optical properties. The crystallographic structure and the size of the crystallites in the films were studied by means of X-ray diffraction. The films had a weak peak (100) orientation at 2theta = sim 32°. X-ray diffraction analysis of the as-deposited ZnO and the film annealed at 850 °C showed a strong ZnO (002) diffraction peak centered at 34.1° and 34.5°, respectively. The (004) peak was seen for film annealed at …
An Investigation On Silar Deposited Cu_Xs Thin Films, Aykut Astam, Yunus Akaltun, Muhammet Yildirim
An Investigation On Silar Deposited Cu_Xs Thin Films, Aykut Astam, Yunus Akaltun, Muhammet Yildirim
Turkish Journal of Physics
A copper sulfide thin film was deposited on glass substrate by successive ionic layer adsorption and reaction method at room temperature, using cupric sulfate and sodium sulfide aqueous solutions as precursors. The structural, surface morphological, optical, and electrical properties of the as-deposited film were investigated via X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, optical absorption, and d.c. 2-point probe methods. The film was found to be amorphous, dense, and uniform. Average atomic percentage of Cu:S in the as-deposited film was calculated as 63:37. The band gap energy of copper sulfide thin film was found to be 2.14 eV …
Iii-Nitride Quantum Dots In Nanowires: Growth, Structural, And Optical Properties, Bruno Daudin
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
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
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
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
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
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
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.
Optical And Magnetic Properties Of (Er, F) Co-Doped Sno_2 Nanocrystals, Vinod Kumar, Sitharaman Uma, Rajamani Nagarajan
Optical And Magnetic Properties Of (Er, F) Co-Doped Sno_2 Nanocrystals, Vinod Kumar, Sitharaman Uma, Rajamani Nagarajan
Turkish Journal of Physics
Uniformly (Er, F) co-doped SnO_2 nanocrystals, obtained by a low-temperature solution-based method, were characterized by a variety of analytical techniques. The structure, morphology, and ratio of the elements were confirmed by PXRD, SEM, and TEM analysis, respectively. From XPS analysis, atomic concentrations of Sn, O, and F were quantified. Interparticle pore size increased significantly (with a mean pore diameter of 25.82 nm) in the co-doped sample. Higher in-plane oxygen vacancies and bands due to multiphonon scattering were observed in the Raman spectrum of the sample. The defect traps in the sample were experimentally determined using TL spectroscopy. A broad intense …