The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2008 11 21 The Effect of magnetic field during the pressT on structural, magnetic and magnetoresistance of la8sr2Mno3 compound The Effect of magnetic field during the pressT on structural, magnetic and magnetoresistance of la8sr2Mno3 compound 185 190 1689 FA M Eshraghi Payamenoor University P Kameli IUT 0000-0003-4490-0767 H Salamati IUT I Abdolhosseini Sarsari IUT 0000-0001-5825-0086 Journal Article 2021 06 15  In this paper, two La0/8sr0/2mno3 samples, isotropic (press without magnetic field) and anisotropic (press with magnetic field) have been prepared. Then we have investigated structural, magnetic and magnetotransport properties of these samples using XRD, SEM, Ac susceptibility and magnetoresistance measurements. These studies show that a magnetic property of anisotropic sample is improved and magnetoresistance is decreased. <br />   In this paper, two La0/8sr0/2mno3 samples, isotropic (press without magnetic field) and anisotropic (press with magnetic field) have been prepared. Then we have investigated structural, magnetic and magnetotransport properties of these samples using XRD, SEM, Ac susceptibility and magnetoresistance measurements. These studies show that a magnetic property of anisotropic sample is improved and magnetoresistance is decreased. <br />  Isotropic magnetoresistance Manganite https://ijpr.iut.ac.ir/article_1689_7c4ede33a62160a19586f6e26eaefacf.pdf
The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2019 11 26 The charge neutral doping effects of Ca-La on the transport and superconductivity properties in Nd-123 superconductors The charge neutral doping effects of Ca-La on the transport and superconductivity properties in Nd-123 superconductors 191 197 724 FA S. R. Ghorbani M. Homaei Journal Article 2019 11 26  Polycrystalline samples of Nd1-xCaxBa2-xLaxCu3O7-δ (with 0.0 ≤ x ≤ 0.15) were prepared by the standard solid state method. The transport and superconducting properties have been studied by the resistivity and thermoelectric power measurements as a function of temperature and doping concentration. With increasing doping concentration, the resistivity was increased and thermoelectric power was constant at high temperature while it was increased slightly at low temperature. The critical temperature Tc was linearly decreased with increasing doping. The density of statets at Fermi energy g(εF) were obtained from the thermoelectric power. They were decreased as x increased. The thermoelectric power as a function of temperature was analyzed in terms of the phenomenological narrow band model. The model well described thermoelectric power data up to near the critical temperature. Severl property results such as the resistivity ρ(x,T), thermoelectric power S(x,T), critical temperature Tc(x) , and g(εF) variation suggested that the hole localization is the main reason of superconducting suppression in the charge neutral doped cuprates.  Polycrystalline samples of Nd1-xCaxBa2-xLaxCu3O7-δ (with 0.0 ≤ x ≤ 0.15) were prepared by the standard solid state method. The transport and superconducting properties have been studied by the resistivity and thermoelectric power measurements as a function of temperature and doping concentration. With increasing doping concentration, the resistivity was increased and thermoelectric power was constant at high temperature while it was increased slightly at low temperature. The critical temperature Tc was linearly decreased with increasing doping. The density of statets at Fermi energy g(εF) were obtained from the thermoelectric power. They were decreased as x increased. The thermoelectric power as a function of temperature was analyzed in terms of the phenomenological narrow band model. The model well described thermoelectric power data up to near the critical temperature. Severl property results such as the resistivity ρ(x,T), thermoelectric power S(x,T), critical temperature Tc(x) , and g(εF) variation suggested that the hole localization is the main reason of superconducting suppression in the charge neutral doped cuprates. superconductivity resistivity thermoelectric power electronic density of state localization https://ijpr.iut.ac.ir/article_724_7f1171a78ce0780a2142a6eb7bc4f3c8.pdf
The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2019 11 26 Computation of the third, fourth and fifth stability regions in a Paul trap Computation of the third, fourth and fifth stability regions in a Paul trap 199 204 725 FA H. Noshad G. H. Janipour-Shahroud-Kolaee Journal Article 2019 11 26  The behavior of ions in a Paul trap has been investigated using numerical solution of the set of Mathieus differential equations. Afterwards, the trajectories of two typical ions such as H+ and 208Pb+ in the trap have been obtained using the fourth-order Runge-Kutta method. For specific dimensions of a Paul trap and a given frequency, the stability regions for separation of H+ and 2H+ ions have been determined in terms of the DC and AC voltages applied to the trap. Furthermore, five stability regions in which ion trapping occurs have been obtained accurately. Computation of the fifth stability region has not been reported in the literature previously.  The behavior of ions in a Paul trap has been investigated using numerical solution of the set of Mathieus differential equations. Afterwards, the trajectories of two typical ions such as H+ and 208Pb+ in the trap have been obtained using the fourth-order Runge-Kutta method. For specific dimensions of a Paul trap and a given frequency, the stability regions for separation of H+ and 2H+ ions have been determined in terms of the DC and AC voltages applied to the trap. Furthermore, five stability regions in which ion trapping occurs have been obtained accurately. Computation of the fifth stability region has not been reported in the literature previously. Paul trap Mathieus equation fourth-order Runge-Kutta method stability regions from the third to fifth ion instability https://ijpr.iut.ac.ir/article_725_82f2b308c3b01637c607ce05f52a2fed.pdf
The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2019 11 26 Dynamical study of the multiquark states Dynamical study of the multiquark states 205 206 726 FA A. Haghpeyma M. Sarbisheie Journal Article 2019 11 26   Diquarks may play an important role in hadronic physics particularly near the phase transitions (chiral, deconfinement points). By using vector diquark ideas in the chiral limit diquark correlations in the relativistic region and imposing HF interactions between quarks in a vector diquark, we calculate the mass of Theta pentaquark state. Also by using the tunnelling method we simultaneously calculate its decay width. Our results are in good agreement with experimental results.   Diquarks may play an important role in hadronic physics particularly near the phase transitions (chiral, deconfinement points). By using vector diquark ideas in the chiral limit diquark correlations in the relativistic region and imposing HF interactions between quarks in a vector diquark, we calculate the mass of Theta pentaquark state. Also by using the tunnelling method we simultaneously calculate its decay width. Our results are in good agreement with experimental results. diquark pentaquark hadron physics quark model https://ijpr.iut.ac.ir/article_726_0d3180d672e08b4c5312dcdafdf6ef36.pdf
The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2019 11 26 Carbon nanotubes doped with trivalent elements by using back - scattering Raman spectroscopy Carbon nanotubes doped with trivalent elements by using back - scattering Raman spectroscopy 219 226 727 FA S. A. Babanejad R. Malekfar M. R. Seyyed Hosseini Journal Article 2019 11 26  In this paper by using DC arc discharge method and acetylene gas, as the carbon source, and nitrogen, as the carrier gas, canrbon nanotubes, CNTs, doped with trivalent element boron, B, have been produced. The deposited CNTs on the cathod electrod, which have structural doped properties to boron element, have been collected and after purification have been investigated by back-scattering Raman spectroscopy. The results reveal that the high frequency G mode component in CNTs doped with electron acceptor element, B, shift to higher wavenumbers. The low frequency G mode component which can appear at approximately 1540–1570 cm-1 wavenumber region, called BWF mode, is a sign of metallic CNT. In the synthesized doped CNTs due to the presence of boron dopant, D mode has sharp peaks and has relatively high intensity in the Raman spectra .  In this paper by using DC arc discharge method and acetylene gas, as the carbon source, and nitrogen, as the carrier gas, canrbon nanotubes, CNTs, doped with trivalent element boron, B, have been produced. The deposited CNTs on the cathod electrod, which have structural doped properties to boron element, have been collected and after purification have been investigated by back-scattering Raman spectroscopy. The results reveal that the high frequency G mode component in CNTs doped with electron acceptor element, B, shift to higher wavenumbers. The low frequency G mode component which can appear at approximately 1540–1570 cm-1 wavenumber region, called BWF mode, is a sign of metallic CNT. In the synthesized doped CNTs due to the presence of boron dopant, D mode has sharp peaks and has relatively high intensity in the Raman spectra . carbon nanotubes CNTs arc discharge Raman spectroscopy https://ijpr.iut.ac.ir/article_727_fb89705ae6d743bf1e848c206e16a1d7.pdf
The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2019 11 26 Study of the moving single bubble sonoluminescence Study of the moving single bubble sonoluminescence 227 234 728 FA M. AliAsgarian S. Z. Kalantari Journal Article 2019 11 26   Moving single bubble sonoluminescence has been discovered after searches to find the fluids other than water for observing SBSL. The main property of these fluids is their more viscosity rather than water. In this paper, after introducing the forces which act on sonoluminescing bubble, the moving of the bubble have been simulated. For this purpose, the bubble’s equation of motion is coupled with the Rayleigh-Plesset and temperature equations. For solving these equations we have used the Runge-Kutta method. We have shown that the path of the bubble is the same as an ellipsoidal movement near the center of the flask. One of the main results of this simulation is that the maximum temperature (at collapse moment) of the bubble is increased by reducing the distance of the bubble from the center of flask. Due to direct relation between light emission and the temperature of the bubble, the same result can be get for intensity of the light. In other words, we have shown that the intensity of the emitted light from bubble oscillates. Accordingly we propose that the measurement of the light oscillation from the moving bubble is as a criterion for experiment on moving single bubble sonoluminescence.   Moving single bubble sonoluminescence has been discovered after searches to find the fluids other than water for observing SBSL. The main property of these fluids is their more viscosity rather than water. In this paper, after introducing the forces which act on sonoluminescing bubble, the moving of the bubble have been simulated. For this purpose, the bubble’s equation of motion is coupled with the Rayleigh-Plesset and temperature equations. For solving these equations we have used the Runge-Kutta method. We have shown that the path of the bubble is the same as an ellipsoidal movement near the center of the flask. One of the main results of this simulation is that the maximum temperature (at collapse moment) of the bubble is increased by reducing the distance of the bubble from the center of flask. Due to direct relation between light emission and the temperature of the bubble, the same result can be get for intensity of the light. In other words, we have shown that the intensity of the emitted light from bubble oscillates. Accordingly we propose that the measurement of the light oscillation from the moving bubble is as a criterion for experiment on moving single bubble sonoluminescence. moving single bubble sonoluminescence Rayleigh-Plesset equation https://ijpr.iut.ac.ir/article_728_d4c2e4a3297fe25a71d030b67eb83bfc.pdf
The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2019 11 26 Structural and electronic properties of cerium from LDA+U calculations Structural and electronic properties of cerium from LDA+U calculations 235 240 729 FA F. Kheradmand S. Jalali Asadabadi Journal Article 2019 11 26  In this work structural, electronic and magnetic properties of alpha and gamma phases of cerium crystal have been calculated by means of the LDA and LDA+U methods. The equilibrium volume and magnetic moment obtained from the GGA approximation in agreement with the experiment are equal to 27.64 Å3 and 0.00018 µB, respectively. This agreement shows that the 4f electrons in alpha phase are itinerant due to the use of the GGA, where no strong correlations have been yet thaken into account. We have observed that even after applying the GGA+U method with U = 6.1 eV, the density of states of f orbital remains still at Fermi surface. Therefore, in complete accord with the experiment, our results show that the 4f electrons in the alpha phase are not localized. This is the case where the LDA and the GGA approximations could not describe the gamma phase properly. Indeed, physical properties of the gamma phase is consistent with the experiment and could only be reproduced after applying LDA+U method with U = 4.4 eV. In this way, the value of equilibrium volume and magnetic moment calculated for the gamma phase were found to be 34.33 Å3 and 1.15 µB, respectively. After including correlations among 4f electrons the γ-Ce DOS is positioned at its more reasonable place lower than Fermi level compared with the DOS obtained from GGA calculations. Our results, then, show that the 4f electrons in the gamma phase, as opposed to the alpha phase, are localized which is indicative of the fact that gamma cerium is a strongly correlated system. The volume of 11 kbar has been obtained for the pressure of the alpha-gamma phase transition .  In this work structural, electronic and magnetic properties of alpha and gamma phases of cerium crystal have been calculated by means of the LDA and LDA+U methods. The equilibrium volume and magnetic moment obtained from the GGA approximation in agreement with the experiment are equal to 27.64 Å3 and 0.00018 µB, respectively. This agreement shows that the 4f electrons in alpha phase are itinerant due to the use of the GGA, where no strong correlations have been yet thaken into account. We have observed that even after applying the GGA+U method with U = 6.1 eV, the density of states of f orbital remains still at Fermi surface. Therefore, in complete accord with the experiment, our results show that the 4f electrons in the alpha phase are not localized. This is the case where the LDA and the GGA approximations could not describe the gamma phase properly. Indeed, physical properties of the gamma phase is consistent with the experiment and could only be reproduced after applying LDA+U method with U = 4.4 eV. In this way, the value of equilibrium volume and magnetic moment calculated for the gamma phase were found to be 34.33 Å3 and 1.15 µB, respectively. After including correlations among 4f electrons the γ-Ce DOS is positioned at its more reasonable place lower than Fermi level compared with the DOS obtained from GGA calculations. Our results, then, show that the 4f electrons in the gamma phase, as opposed to the alpha phase, are localized which is indicative of the fact that gamma cerium is a strongly correlated system. The volume of 11 kbar has been obtained for the pressure of the alpha-gamma phase transition . strongly correlated systems LDA+U method Cerium crystal 4f electrons alpha phase gamma phase https://ijpr.iut.ac.ir/article_729_5751ec3e9a4feab575962e78e006250d.pdf
The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2019 11 26 Simulation of doping type and current density effects on porous silicon growth by modified limited diffusion aggregation method Simulation of doping type and current density effects on porous silicon growth by modified limited diffusion aggregation method 241 248 730 FA S. Minaeifard R. Dariani Journal Article 2019 11 26   The aim of this article is apply modification to limited diffusion aggregation model. The method can simulate the doping type and current density on obtained structures forms within porous silicon growth. For doping type effect, the sticking coefficient parameter and for the current density effect, mean field parameter applied to limited diffusion aggregation. Simulation results showed that the sticking coefficient parameter influences pores thickness controlling. Meanwhile, the mean field parameter could control tree or rod characteristics of pores. Results on porous silicon growth simulation showed that the applied modifications accompany with these two parameters on structure simulation formation are consistence with experimental data of the samples.   The aim of this article is apply modification to limited diffusion aggregation model. The method can simulate the doping type and current density on obtained structures forms within porous silicon growth. For doping type effect, the sticking coefficient parameter and for the current density effect, mean field parameter applied to limited diffusion aggregation. Simulation results showed that the sticking coefficient parameter influences pores thickness controlling. Meanwhile, the mean field parameter could control tree or rod characteristics of pores. Results on porous silicon growth simulation showed that the applied modifications accompany with these two parameters on structure simulation formation are consistence with experimental data of the samples. porous silicon limited diffusion aggregation simulation sticking coefficient mean field https://ijpr.iut.ac.ir/article_730_d5cfead94f5350c12c322b5b664544c1.pdf
The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2019 11 26 Electronic conduction of poly(dG)-poly(dC) DNA in SWNT/DNA/SWNT structure Electronic conduction of poly(dG)-poly(dC) DNA in SWNT/DNA/SWNT structure 249 249 731 FA S. A. Ketabi A. Ahmadi Fouladi N. Shahtahmasebi Journal Article 2019 11 26   In this work, using a tight-binding Hamiltonian model, a generalized Greens function method and Löwdins partitioning techniques, some of the significant properties of the conductance of poly(dG)-poly(dC) DNA molecule in SWNT/DNA/SWNT structure are numerically investigated. In Fishbone model, we consider DNA as a planar molecule which contains M cells and 3 further sites (one base pair site and two backbone sites) in each cell sandwiched between two semi-infinite single-walled carbon nanotubes(SWNT) as the nano-electrodes. Relying on Landauer formalism as the basis for investigating the conductance properties of this system, we focus on the studying of the electron transmission and the current-voltage characteristics of DNA in the foregoing structure. In addition, in the presence of the electric potential between DNA molecule ends, our results suggest that the increasing of the value of applied bias give rise to the large enhancement in the conductance of the system. We also find that, as the tube radius increases, the conductance of the system considerably increases.   In this work, using a tight-binding Hamiltonian model, a generalized Greens function method and Löwdins partitioning techniques, some of the significant properties of the conductance of poly(dG)-poly(dC) DNA molecule in SWNT/DNA/SWNT structure are numerically investigated. In Fishbone model, we consider DNA as a planar molecule which contains M cells and 3 further sites (one base pair site and two backbone sites) in each cell sandwiched between two semi-infinite single-walled carbon nanotubes(SWNT) as the nano-electrodes. Relying on Landauer formalism as the basis for investigating the conductance properties of this system, we focus on the studying of the electron transmission and the current-voltage characteristics of DNA in the foregoing structure. In addition, in the presence of the electric potential between DNA molecule ends, our results suggest that the increasing of the value of applied bias give rise to the large enhancement in the conductance of the system. We also find that, as the tube radius increases, the conductance of the system considerably increases. DNA electronic transmission carbon nanotube Fishbone model Greens function https://ijpr.iut.ac.ir/article_731_59c33016884a62116be975a9bb8257e3.pdf
The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2019 11 26 Energy dependent fractal dimension in lateral electron distribution of extensive air showers Energy dependent fractal dimension in lateral electron distribution of extensive air showers 250 250 732 FA D. Purmohammad F. Bahreini Davarani Journal Article 2019 11 26   Secondary electrons at ground level of simulated extensive air showers have been analyzed using a wavelet transform based technique, in order to investigate the variation of fractal dimensions of the lateral distribution of the electrons with shower energy and primary particle mass number. The fractal dimension is shown to increase with shower energy and seems to saturate to constant values near the core of the shower at higher energies. Using the fractal dimension properties at different core distances, a multi-parameter separation technique is then applied to the data. It has been shown that the technique has good accuracy at high energy, provided the energy of the shower is obtained independently.   Secondary electrons at ground level of simulated extensive air showers have been analyzed using a wavelet transform based technique, in order to investigate the variation of fractal dimensions of the lateral distribution of the electrons with shower energy and primary particle mass number. The fractal dimension is shown to increase with shower energy and seems to saturate to constant values near the core of the shower at higher energies. Using the fractal dimension properties at different core distances, a multi-parameter separation technique is then applied to the data. It has been shown that the technique has good accuracy at high energy, provided the energy of the shower is obtained independently. cosmic rays extensive air showers https://ijpr.iut.ac.ir/article_732_ba3866600c3540f67c1e9575e213be0a.pdf
The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 8 4 2019 11 26 The effect of MgO nano-particles on Bi-2223 high temperature superconductors prepared by chemical sol-gel method The effect of MgO nano-particles on Bi-2223 high temperature superconductors prepared by chemical sol-gel method 267 273 733 FA M. Eshraghi P. Kameli 0000-0003-4490-0767 H. Salamati E. Abdolhosseini Sarsari Journal Article 2019 11 26  In this paper, two La0/8sr0/2mno3 samples, isotropic (press without magnetic field) and anisotropic (press with magnetic field) have been prepared. Then we have investigated structural, magnetic and magnetotransport properties of these samples using XRD, SEM, Ac susceptibility and magnetoresistance measurements. These studies show that a magnetic property of anisotropic sample is improved and magnetoresistance is decreased.  In this paper, two La0/8sr0/2mno3 samples, isotropic (press without magnetic field) and anisotropic (press with magnetic field) have been prepared. Then we have investigated structural, magnetic and magnetotransport properties of these samples using XRD, SEM, Ac susceptibility and magnetoresistance measurements. These studies show that a magnetic property of anisotropic sample is improved and magnetoresistance is decreased. superconductor Sol-gel Bi(Pb)SrCaCuO MgO https://ijpr.iut.ac.ir/article_733_6c29793a140a811d0c45ce03c1c93a28.pdf