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Conference Object Citation - WoS: 7Citation - Scopus: 7Synthesis, Characterizations and Investigation of Thermoluminescence Properties of Strontium Pyrophosphate Doped With Metals(Pergamon-elsevier Science Ltd, 2014) Ilkay, L. S.; Ozbayoglu, G.; Yilmaz, A.Strontium pyrophosphate, Sr2P2O7, was synthesized by solid-state synthesis method; the product was co-doped with copper-silver (Cu-Ag), copper-indium (Cu-In) and manganese-praseodymium (Mn-Pr) oxides (CuO, MnO, In2O3, Pr6O11 and AgNO3) by solid-state reaction method. The variation of dopant concentrations was investigated from 0.5 to 15% by weight. In addition to these processes, chemical characterizations of samples and the investigation of thermoluminescence (TLD) properties of strontium pyrophosphate with and without dopants were conducted. For the characterization; powder X-ray Diffraction (XRD) were implemented for phase purity of samples. Fourier Transform Infrared Spectroscopy (FTIR) was used to determine whether the bond structures were affected from the doping or not. Thermoluminescence (TLD) analyses were conducted on strontium pyrophosphate doped with different amounts of dopants for the first time. Glow curves showed that intensities were affected by different amounts of dopants. It can be concluded from that strontium pyrophosphate doped with 7% MnO and 1% Pr6O11 had the most powerful peak intensity around 160 degrees C and dosimetric property for promising application. (C) 2014 Elsevier Ltd. All rights reserved.Article Citation - WoS: 22Citation - Scopus: 24Mechanical and Biological Properties of Al2o3< and Tio2 Co-Doped Zirconia Ceramics(Elsevier Sci Ltd, 2017) Agac, Ozlem; Gozutok, Melike; Sasmazel, Hilal Turkoglu; Ozturk, Abdullah; Park, JongeeVarious amounts (ranging from 0 to 2 wt%) of TiO2 and Al2O3 were mono and co-doped to tetragonal zirconia ceramic containing 3 mol% yttria (3Y-TZP) by mechanical ball milling. Powders were compacted by uniaxial pressing at a pressure of 23 MPa. The compacts were pressureless sintered at 1450 degrees C for 2 h. Density, hardness, fracture toughness, and cell attachment of the co-doped 3Y-TZP ceramics were measured with respect to dopant addition to determine the effects of the kind and amount of dopants on the properties. The results show that density decreased gradually as the amount of dopant was increased. The mechanical properties showed the maximum value when 0.5 wt% TiO2 and 1.0 wt% Al2O3 were co-doped to 3Y-TZP. Crystalline phase formation and microstructural morphology were investigated by XRD and SEM analyses to explain the variations in the properties. Co-doping of TiO2 and Al2O3 to 3Y-TZP did not have an influence on the phases present, but decreased the grain size. The co-doping also affected the cell attachment and the growth on the surface of the zirconia ceramics.Article Citation - WoS: 50Citation - Scopus: 54The Effect of Synthesis and Doping Procedures on Thermoluminescent Response of Lithium Tetraborate(Elsevier Science Sa, 2011) Pekpak, E.; Yilmaz, A.; Ozbayoglu, G.Lithium tetraborate has been a scientific focus since 1960s by the courtesy of the thermoluminescence property it possesses. Moreover, it is utilized in surface acoustic wave apparatuses, in sensor sector and in laser technology owing to its non-linear optical characteristics. For the uses in thermoluminescence dosimetry lithium tetraborate is activated by addition of a variety of metals as dopants. This study includes the synthesis of lithium tetraborate by two methods (high temperature solid state synthesis and water/solution assisted synthesis), doping of activators into the matrix material synthesized and characterization of the products. Lithium tetraborate is readily commercially available in TL (Themoluminescence) dosimetry; hence, the main aim in this study was to specify the effect of synthesis and doping methods on the TL response. The heating temperature for the synthesis was 750 degrees C and the retention time as selected as 4 h for both methods. The synthesis stages were followed by doping step where the compounds of Cu, Ag and In in different proportions were doped in lithium tetraborate by solid state and solution assisted doping techniques. Characterization of the product was achieved by X-ray diffraction (XRD). Fourier transform Infra Red Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) techniques. All samples prepared displayed TL response and the best TL signal was obtained from the sample produced by solid state synthesis and doped by solution assisted method with 0.1% Cu and 0.004% Ag. (C) 2010 Elsevier B.V. All rights reserved.Article Citation - WoS: 18Citation - Scopus: 19Synthesis and Enhanced Photocatalytic Activity of Molybdenum, Iron, and Nitrogen Triple-Doped Titania Nanopowders(Elsevier Sci Ltd, 2016) Erdogan, Nursev; Park, Jongee; Ozturk, AbdullahA novel Mo, Fe, and N triple-doped rutile TiO2 nanopowder was synthesized with simple HNO3 assisted hydrothermal treatment. Powders synthesized were characterized by using x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and Brunauer-Emmett-Teller (BET) surface area analysis techniques. Mo doping initiated the formation of a structure composed of a mixture of anatase and rutile with some modifications in morphology; but Mo, Fe, and N triple-doped titania powders are composed of entirely rutile structures. XPS analysis confirmed that Mo dissolved in the structure, replacing Ti atoms and forming some MoO3 partially crystallized nano regions on the surface. Existence of Fe in the TiO2 crystal lattice was confirmed by ICP analysis. Fe doping had an influence on the crystal structure and morphology. N was found to be dissolved in the co-doped structure by HNO3 catalyzer autogenously. Methylene blue degradation testing and band gap measurements were performed by using UV-vis photospectroscopy and diffuse reflector apparatus in order to evaluate the photocatalytic performance of the powders. Dopant elements decreased band gap energy steadily. An enhanced photoactivity was reached by Mo, Fe, and N triple-doping as compared with that of undoped, and mono doped TiO2 powders under UV-light irradiation. Possible reasons for the enhancement in photocatalytic activity are outlined. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
