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The Correlation of Miller Indices with the Conductivity Mechanism of Cu-Based High-Tc Superconductor

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Journal of Modern Physics 2017年第8期8卷 1143-1151页

作者： Israa Maher emad k. al-shakarchi Physics Department College of Science Al-Nahrain University Baghdad Iraq

The high temperature superconductor of CuBa2Ca2Cu3O8+δ(Cu-1223) was synthesized experimentally by solid-state reaction. There were many pa-rameters affecting the preparation technique such as oxygen flow, sintering temperature, sintering time, and compacted pressure. The XRD-pattern exhibited a tetragonal phase for both Cu-1223, and Cu-1212. The resistivity measurement was considered the important experiment to show the predominant phase of superconductor if it was a high phase or low phase. The critical temperature (Tc) was about (128 k. for the high phase of Cu-1223, whereas the low phase of (Cu-1212) appeared at (Tc = 64 k.. The correlation between the Miller indices and resistivity measurements was a good tool to predicate the expected mechanism of conductivity within the unit cell. It was clear that the arrangement of these planes was aligned in the a-c direction. That should mak. the motion of the charge to be simpler by a stepping plane toward c-axis.

关键词： Solid-State Reaction High-Tc Superconductor Resistivity Measurement XRD-Pattern SEM Analysis

Three Techniques Used to Produce BaTiO3Fine Powder

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Journal of Modern Physics 2011年第11期2卷 1420-1428页

作者： emad k. al-shakarchi Natheer B. Mahmood 不详

Homogeneous BaTiO3 fine powder has been synthesized at (80°C) by using three different chemical methods using the roots TiCl4, BaCl2 and NaOH or Oxalic acid. The resultant powders were characterized using x-ray diffraction (XRD) to estimate the crystal structure, lattice parameters and the crystallite size to investigate the favor method in producing BaTiO3 fine powder. The criteria that was dependent on considering the favor method that was given better results of XRD and demand a least time in preparation which tend to consume a lowest energy.

关键词： X-Ray Diffraction Fine Powder Williamson-Hall Method

Simulation and Experimental Data of P-E Hysteresis Loop in BNT and Bk.

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Journal of Modern Physics 2017年第5期8卷 844-851页

作者： Natheer B. Mahmood emad k. al-shakarchi Physics Department College of Science Al-Nahrain University Baghdad Iraq

Hysteresis loop measurements performed both experimentally for Bismuth Sodium Titanate (BNT) and Bismuth Potassium Titanate (Bk.) samples using modified Sawyer-Tower Circuit. The experiment showed that the P-E hysteresis had main parameters for BNT, remnant polarization (Pr = 27 μC/cm2), spontaneous polarization (Ps = 35 μC/cm2) and coercive electric field (Ec = 60 k./cm) and for Bk. the remnant polarization was (Pr = 5.2 μC/cm2), spontaneous polarization (Ps = 30 μC/cm2) and coercive electric field (Ec = 4.72 k./cm). These three parameters (remnant polarization, spontaneous polarization, coercive electric field) were used in a simulated software depending on the mathematical model for the polarization in ferroelectric materials. The simulation software predicted the value of applied electric field required to perform the P-E hysteresis experiment varying with Pr, Ps, Ec. The results of the simulation exhibited agreement with the experimental data. The last prediction could help the researchers in studying the ferroelectric hysteresis loop, especially for those studying a fatigue behaviour or studying the effect of electric field cycle on the hysteresis loop.

关键词： Ferroelectric Behaviour Fatigue Behaviour Hysteresis Loop Perovsk.te Structure

The Preparation of Nano Silver by Chemical Reduction Method

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Journal of Modern Physics 2022年第1期13卷 81-88页

作者： Tevfik.Raci Sertbak.n emad k. al-shakarchi Saif Sultan Mala k.#305 r&scedil ehir Ahi Evran University Art and Science Faculty Department of Physics K&#305 r&scedil ehir Turkey al-Nahrain University College of Science Physics Department Baghdad Iraq

A silver nanostructures prepared by using chemical reduction method. The silver nanoparticles were prepared with diameters of about (20 nm). Numerous techniques had been used to study the optical, structural lik. the UV-Vis absorption spectrometer, Ttransmission Electron Microscopy (TEM), Field-Emission Scanning Electron microscope (FESEM), and X-ray diffraction (XRD). The practical results exhibited the absorption spectrum of the prepared nanoparticles at (357 nm), it was found that there is a relationship between the positions of the optical absorption peak.and the size of the silver nanoparticles. The analysis of TEM results showed the presence of nanoparticles in the range (20 nm). The analyzing of XRD results explained the crystal structure for silver nanoparticles. It is found a cubic unit cell have a lattice constants (a = 4.0855 Å), with the Miller indices were (111), (002), (002), and (113).

关键词： Chemical Reduction Method UV-Vis Absorption Spectrometer Field-Emission Scanning Electron Microscope Ttransmission Electron Microscopy

The Effect of Gold Salt Concentration in the Production of Gold Nanospheres

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Journal of Applied Mathematics and Physics 2020年第8期8卷 148-1495页

作者： Sabreen Juda Badi emad k. al-shakarchi Shyma’a Jamal Ahmed Physics Department College of Science Al-Nahrain University Baghdad Iraq College of Medicine University of Baghdad Baghdad Iraq

The optical, electrical and chemical properties of the gold nanospheres synthesized by different gold concentrations in deionized water through a simple chemical reduction method (Turk.vich method) were studied. They were dependent on the variation of the gold salt concentration. The peak. of the surface Plasmon resonance (SPR) absorption band and their wavelengths were detected by a UV-visible spectrophotometer. The diameters of the spherical gold nanoparticles were measured theoretically using UV-visible absorption spectrum analysis of the synthesized gold nanoparticles in colloidal form by calculating the ratio of the absorbance at the surface Plasmon resonance (SPR) peak.to the absorbance at the lowest peak.closed to SPR peak. The values of the gold nanoparticles diameters were (23 nm) and decreased to (13 nm) as the function of molarity changed in the range (0.1 - 0.3 mM). They were compared with the results of the transmission electron microscopy (TEM), which was about (15 - 20 nm) measured by the reference images of Sigma-aldrich values. The conductivity measurements showed increasing the conductivity with molarity increased. The total dissolved solids (TDS) exhibited increase by linear relation with molarity increasing. The pH-value of the gold nanoparticles solutions varied with the molarity and recorded a bowing value of pH-value at (0.2 mM).

关键词： Gold Nanoparticles Turk.vich Method Surface Plasmon Resonance Total Dissolved Solids Conductivity Measurements

New High Tc-Value Investigated in Superconducting System YBa2（C u3）1-xA gxO6.5x＋δ

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Journal of Physical Science and Application 2012年第9期2卷 352-358页

作者： emad k. al-shakarchi Salwan k.J. al-Ani Wedad. M. Faysal Physics Department College of Science Al-Nahrain University Baghdad Iraq Physics Department College of Science Baghdad University Baghdad Iraq

A ceramic superconductor compound with composition YBa2（C u3）1-xA gxO6.5x＋δhas been prepared experimentally by solid state reaction from principal roots of high purity materials lik. Y203, BaO, CuO and Ag20. The study was concentrated on the effect of partial substitution of Ag with respect to Cu atoms by the ratios （x = 0, 1, 0.2, 0.3, 0.4 and 0.5） through different analysis and measurements. X-ray diffraction （XRD）, Scanning Electron Microscope （SEM） and Resistivity measurement is play an important role to show the improvement on high superconducting phase. It was found that the best substituted value of （x = 0.5） investigated a favor value of Tc equal nearly to （123 k., due to more excess of Ag atoms in the structure. X-ray diffraction showed an orthorhombic structure related to high-To phase with high stability through diminishing some peak. related to low temperature superconducting phase, that was related to presence of multiphase derivative from YBCO-phase. SEM pictures give us more details on the surface morphology, grain and grain boundaries, it gives an indication on successful of sintering process, the last one is very important in forming superconducting phase.

关键词： Superconductor compound 123-compound resistivity measurements X-ray diffraction.

Crystal Structure of BaxSr1-xTiO3Fine Powder

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Journal of Modern Physics 2015年第1期6卷 70-77页

作者： Natheer B. Mahmood emad k. al-shakarchi Brahim Elouadi Xavier Feaugas Physics Department College of Science Al-Nahrain University Baghdad Iraq Laboratoire des Sciences de l’Ingénieur pour l’Environnement Université de La Rochelle La Rochelle France

Various compositions of the system BaxSr1-xTiO3 (BST) have been elaborated both as fine powders and ceramic monoliths, using the co-precipitation route within a warmed supersaturated solution of oxalic acid. The appropriate stoichiometry was determined from the mixtures of precisely titrated aqueous solutions of cations chlorides (SrCl2, BaCl2, and TiCl4). The reason of this process was to apply low sintering temperature in production of BST samples with ultra-fine powders. These powders primarily calcined at (850°C) for (5 hr) were used to elaborate ceramics after pellets sintering at (1200°C) during (8 hrs). Indeed, XRD patterns were confirmed that the samples are a pure phase and a perovsk.te cubic structural type at (x = 0, 0.5, 0.6). Whereas, (x = 0.7, 0.8, 0.9, 1) showed a tetragonal phase. There is agreement between the FTIR and XRD analysis, by the relation of the wave vector (k. and lattice constant. It was deduced a stimulated relation between (x) and (k.. The results of TEM, they were clear that the lowest particle sizes investigated of BST powders nearly (36 - 50 nm).

关键词： Barium Strontium Titanate Oxalate Co-Precipitation Method X-Ray Diffraction Transmission Electron Microscope Ultra-Fine Powder

Dielectric properties of BNT-xBT prepared by hydrothermal process

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Journal of Advanced Dielectrics 2017年第3期7卷 29-36页

作者： Natheer B.Mahmood emad k.al-shakarchi Physics Department College of Science Al-Nahrain UniversityBaghdadIraq

The BNT ceramic sample might be a good replacement for PZT piezoelectric in industrial applications,especially in energy harvesting from crystal *** order to enhance the performance of BNT ceramic,the solid solution was chosen by substitution with Ba+2 at Morphtropic Phase Boundary(MPB).The BNT-xBT powders with x=1,0.07,0.06 and 0 were prepared by the hydrothermal method with average particle size(65–150 nm)at(90℃/72 h).The ceramic disc was sintered at(1150℃/4 h)and showed excellent relative density of about 96%.The results of X-ray diffraction(XRD)confirmed the MPB for x=0:06 and 0.07,while the BNT had a rhombohedral structure and BT had a tetragonal *** dielectric measurements showed that BNT,BNT-7BT,BNT-6BT behave as the relaxator ferroelectric and showed a strong dependence on frequency,especially in the MPB region while BT behaves as a normal *** the Curie temperature and depolarization temperature decrease at the MPB region and showed strong dependency on frequency.

关键词： Ferroelectric behavior piezoelectric behavior energy harvesting hydrothermal process.

The nanostructure of barium dititanate prepared by hydrothermal method

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Journal of Advanced Dielectrics 2019年第2期9卷 7-13页

作者： Sarah L.Rasheed emad k.al-shakarchi Physics Department College of Science Al-Nahrain UniversityBaghdadIraq

The dielectric ceramic of barium dititanate compound BaTi_(2)O_(5) had been prepared through the hydrothermal process by applying different parameters,such as pH-value,reaction time,temperature and *** prepared powders were examined by X-ray diffraction(XRD).The predominant phase was a monoclinic phase with lattice constants(a=16:6381,b=3:555,c=9:3406Å),(β=107:47°,α=γ=90°),and the unit cell volume(527Å^(3)).The surface morphology was demonstrated by Scanning Electron Microscopy(SEM).It exhibited the grains in spherical and elliptical shapes with high *** shapes of nanostructure were analyzed by Transmission Electron Microscopy(TEM).The appearance of nanostructures lik. the nanoparticles and nano rods were *** size of nanoparticles was in the range of 9–31 nm,and size of nanorods was 32–37 *** dielectric measurements were done by using LCR meter at different temperature and frequencies(10,50 and 100 k.z).It was clear that the Curie temperature had a high value up to(485℃).The relative permittivity was partially changed for two prepared samples regarding high pressure and long reaction time,which were the main preparation conditions of hydrothermal method.

关键词： Barium dititanate hydrothermal method nanostructures monoclinic phase dielectric properties