Al-Azhar University, Faculty of Science (Boys)Al-Azhar Bulletin of Science1110-253528Issue 2-D20170601STUDY THE THERMAL AND ELECTRICAL PROPERTIES OF SOME MAGNESIUM-BORO-PHOSPHATE GLASSES CONTAINING VANADIUM OXIDE.110817210.21608/absb.2017.8172ENA. A.BendaryPhys. Dept., Faculty of Science, Al-Azhar Univ., Nasr City, Cairo, Egypt.Journal Article20170115<span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>Glasses having the molecular composition 20 M</em></span></span><sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>g</em></span></span></sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>O - 30 B</em></span></span><sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>2</em></span></span></sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>O</em></span></span><sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>3</em></span></span></sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em> - (50-x) P</em></span></span><sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>2</em></span></span></sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>O</em></span></span><sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>5</em></span></span></sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em> – x V</em></span></span><sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>2</em></span></span></sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>O</em></span></span><sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>5</em></span></span></sub><span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em> –- (x = 0, 5, 10, 15 and 20 mol %) have been prepared by the conventional melt quenching method. The thermal and electrical transport properties of the prepared glasses were thoroughly investigated by using differential thermal analysis technique and LCR meter-bridge with four fixed frequencies.</em></span></span><br /> <span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>All the obtained thermal parameters are found to depend on the composition and heating rate. Both the activation energy of glass transition and activation energy of crystallization as well as the thermal stability are found to increase with the gradual increase of vanadium oxide content. </em></span></span><br /> <span style="font-family: Times New Roman,Times New Roman,serif;"><span style="font-size: small;"><em>It was found that, all samples exhibit semi-conduction properties and the conduction mechanism was found to be the small polaron hoping at relatively low temperatures while at relatively higher temperatures, the correlated barrier hoping model was found to be dominant. Also, as vanadium oxide was gradually increased, the conductivity, dielectric constant and dielectric loss factor exhibit gradual increase. </em></span></span>Al-Azhar University, Faculty of Science (Boys)Al-Azhar Bulletin of Science1110-253528Issue 2-D20170601THERMOLUMINESCENCE PROPERTIES OF ERBIUM DOPED SrSO41116817310.21608/absb.2017.8173ENA. M.MoanesPhysics Dept., Faculty of Science Al-Azhar University, Cairo, Egypt.Journal Article20170207<span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>SrSO</em></span></span><sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>4</em></span></span></sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> (</em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>strontium sulphate)</em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> has been prepared by the chemical precipitation technique and characterized by XRD and TEM (Transmission Electron Microscopy). TEM shown the formation of compound in ring like structure with average particle size 45 nm. The erbium (Er) doped to SrSO</em></span></span><sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>4 </em></span></span></sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>by different concentrations for the sake of improving the TL-sensitivity of SrSO4, were found the optimum concentration of erbium is (22wt%). SrSO</em></span></span><sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>4</em></span></span></sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>:Er (0.22wt%) has five glow peaks at (116.5 </em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>˚C</em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> – 183 </em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>˚C</em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> – 344 </em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>˚C</em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> – 412 </em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>˚C</em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> – 431 </em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>˚C</em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>). High gamma doses as TL-sensitization method have been used. By these means the TL-intensity of treated samples proved about 30 times enhancement, which make it very promising detector and dosimeter suitable for ionizing radiation. </em></span></span>Al-Azhar University, Faculty of Science (Boys)Al-Azhar Bulletin of Science1110-253528Issue 2-D20170601INFLUENCE OF PH AND TEMPERATURE ON SURFACE-ACTIVE PROPERTIES OF SOME HUMIC ACIDS1726817410.21608/absb.2017.8174ENA. A.El-BayaaFaculty of Science, Al-Azhar University (Girls). Cairo, EgyptAsmaaAl-AmirFaculty of Science, Al-Azhar University (Girls). Cairo, EgyptJournal Article20170101<span style="font-family: Calibri,sans-serif;"><span style="font-size: small;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em><span style="background: #ffffff;">In this study, surface tension measurements were used to</span></em></span></span><em><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><span style="font-style: normal;"><span style="background: #ffffff;"> study the </span></span></span></span></em><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>surface-active properties of olive humic acid (HAO) and commercial humic acid (HA2). </em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em><span style="background: #ffffff;">The study was performed under different conditions of concentration, temperature, pH and time. The measurements showed that the amphiphilic character of the humic acids solutes</span></em></span></span><span style="color: #000000;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> at the air/water interface lowers the surface tension (</em></span></span></span><span style="color: #000000;"><span style="font-family: Symbol,serif;"><span style="font-size: small;"><em></em></span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>) of the solution</em></span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> with an increasing concentrations and temperatures</em></span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>. The critical micelle concentration (CMC)</em></span></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> values of both humic acids decreased with an increase in the temperature.</em></span></span><span style="color: #000000;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> Positive values of ∆S</em></span></span></span><span style="color: #000000;"><sup><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>o</em></span></span></sup></span><span style="color: #000000;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> and ∆H</em></span></span></span><span style="color: #000000;"><sup><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>o </em></span></span></sup></span><span style="color: #000000;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>suggested that, their adsorption at air/water interface, is endothermic and entropy driven. </em></span></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>The surface tension–pH curve featured a minimum for both humic solutions, declining from higher and lower pH values.</em></span></span></span></span>
Al-Azhar University, Faculty of Science (Boys)Al-Azhar Bulletin of Science1110-253528Issue 2-D20170601LUMINESCENCE INVESTIGATION OF POWDER ZNO NANOPARTICLES DOPED WITH SM AND LI IONS PREPARED BY COPRECIPITATION METHOD2733817510.21608/absb.2017.8175ENH.HantourFaculty of Science, Physics Department, Al-Azhar University (Girls), Cairo, EgyptN. A.MohsenFaculty of Science, Physics Department, Al-Azhar University (Girls), Cairo, EgyptS. N.El-SayedFaculty of Science, Physics Department, Al-Azhar University (Girls), Cairo, EgyptA. M.MahmoudFaculty of Science, Physics Department, Al-Azhar University (Girls), Cairo, EgyptJournal Article20170211<span style="font-family: Calibri,sans-serif;"><span style="font-size: small;"><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>The present study focuses on the structural and optical properties of ZnO doped with Sm and Li at very dilute concentrations, with compounds</em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> Zn</em></span></span><sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>1-x-y</em></span></span></sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>Sm</em></span></span><sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>x</em></span></span></sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>Li</em></span></span><sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>y</em></span></span></sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>O (x = 0, 0.03 and y =0, 0.01, 0.03, 0.05). </em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>These compounds have been synthesized by a chemical coprecipitation method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman microscopy. </em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>The XRD pattern of all the samples showed ZnO hexagonal wurtzite structure, </em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>sharp and intense peaks with small change in lattice parameters due to doping in ZnO, indicating the substitution of Sm and Li ions for Zn sites. For Raman spectra, the strongest peak centered at about 435-437 cm</em></span></span><sup><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>-1</em></span></span></sup><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em> can be observed in all the samples, and the intensity of this peak decreases with Sm doping and increases with Li doping</em></span></span><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>. The optical properties of the samples were systematically studied by ultraviolet-visible spectroscopy (UV-V) and photoluminescence (PL) spectroscopy. The maximum absorption of ZnO and Zn</em></span></span><sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>0.97</em></span></span></sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>Sm</em></span></span><sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>0.03</em></span></span></sub><span style="font-family: Times New Roman,serif;"><span style="font-size: small;"><em>O samples appears around 370 and 374 nm respectively near the absorption edge. Doping with Li affects the absorption edge and make it shift toward ultra violet and that the absorption increase with increasing Li content. The PL spectra show a broad and strong visible emission at 564 nm emission covering a large part of the visible region indicating the presence of intrinsic defects like vacancies. </em></span></span></span></span>Al-Azhar University, Faculty of Science (Boys)Al-Azhar Bulletin of Science1110-253528Issue 2-D20170601IMPACT OF CuO CONTENT ON THE DIELECTRIC PROPERTIES OF ZINC SODIUM PHOSPHATE GLASSES CONTAINING Al2O32735817610.21608/absb.2017.8176ENH. A.ElshaikhPhysics Department, Faculty of Science, Aswan University, Aswan, EgyptY. H.ElbasharPhysics Department, Faculty of Science, Aswan University, Aswan, EgyptAli M.IbrahimandPhysics Department, Faculty of Science, Aswan University, Aswan, EgyptA. G.MostafaPhysics Department, Faculty of Science, Al-Azhar University, (11884) Nasr City, Cairo-EgyptJournal Article20170101<span style="font-size: small;"><em>Dielectric properties of some copper sodium phosphate glasses containing alumina have been studied in the frequency range from 1.05 to 100 kHz under vacuum (10</em></span><sup><span style="font-size: small;"><em>-5</em></span></sup><span style="font-size: small;"><em>torr). The dielectric parameters e.g. dielectric constant, dielectric loss, dielectric loss tangent</em></span><span style="font-size: small;"><em>and ac conductivity, have been calculated. The frequency dependence of the dielectric constant indicates the presence of dipole electric polarization due to linking of one Cu</em></span><sup><span style="font-size: small;"><em>2+</em></span></sup><span style="font-size: small;"><em> ion with two non-bridging oxygens and ionic polarization due to the </em></span><span style="font-size: small;"><em>accumulation of sodium ions at the interfaces. The frequency dependence of the dielectric loss indicates that the conduction is a dominant contribution to the energy loss. </em></span><span style="font-size: small;"><em>The ac conductivity measurements exhibit the coexistence of electronic (due to the electron hopping from Cu</em></span><sup><span style="font-size: small;"><em>+</em></span></sup><span style="font-size: small;"><em> to Cu</em></span><sup><span style="font-size: small;"><em>2+</em></span></sup><span style="font-size: small;"><em> ions) and ionic (due to the mobility of sodium ions). </em></span>