Structural and optical properties of semiconducting nanomaterials: europium doped gadolinium zirconate and yttrium vanadate, cadmium teluride and ruthenium modified zinc - oxide

У овој докторској дисертацији представљена је синтеза, као и структурна и оптичка карактеризација четири репрезентативна прeдставника полупроводничких наноматеријала на бази халкогенида: гадолинијум – цирконата, хемијске формуле Gd2Zr2O7 и итријум – ванадата, YVO4, допираних јонима еуропијума, кадмијум телурида, CdTe, и цинк – оксида, ZnO, модификованог рутенијумовим комплексима. За синтезу ова четири материјала коришћена су четири метода синтезе: метод сагоревања гела, за припрему Gd2Zr2O7, метод сагоревања гела и синтеза реакцијом у чврстој фази, за припрему YVO4, метод високовакуумског напаравања за припрему CdTe и преципитациони метод за припрему ZnO...In this doctoral disseration, synthesis, as well as structural and optical properties of four chalcogenide semiconducting nanomaterials representatives were presented: europium doped gadolinium – zirconate, with chemical formula Gd2Zr2O7 and yttrhrium – vanadate, YVO4, cadmium – telluride, CdTe, and ruthenium modified zinc – oxide , ZnO. For synthesis of these four materials four methods were used: solution combustion synthesis for Gd2Zr2O7, solution combustion synthesis and classical ceramics method for YVO4, thermal evaporation method for CdTe and precipitation method for ZnO..

THE CULTURE OF MEMORY AS A RESPONSE TO THE POLITICS OF REVISION AND OBLIVION... : DIANA JOHNSTONE, EVEANN PRENTICE, AND ELENA GUSKOVA ON THE KOSOVO WAR AND NATO BOMBING OF YUGOSLAVIA

This paper is part of the research carried out on the project "Yugoslav Wars: another face of European civilisation? Lessons learnt and enduring challenges" co-funded by the Europe for Citizens Programme of the European Union. It was presented at the international roundtable On the Phenomenon of War, on the Culture of Peace: Reflections, Analyses, Experiences, University of Kragujevac, February 6th, 2017.This paper deals with the texts by the American journalist and philologist Diana Johnstone, the British journalist Eve-Ann Prentice, and the Russian historian Elena Guskova. We shall focus on the analysis of the attitudes and insights which they have gained in their researches regarding the topics of the Kosovo and Metohija War and NATO bombing of Yugoslavia. Although it is othen heard that it is difficult to write about newer history, including wars immediately ather their termination, that it is necessary to deflect, let the events settle down and create a certain temporal distance, it does not always have to be so – a specific danger is hidden in the act of waiting, which stems from the progressive amnesia induced by the contemporary culture. Thus the question of the Yugoslav wars of the Nineties needs to be actualized, so that it does not become subjected to oblivion or, even worse, to radical revisions.Publishe

Victimization of Serbs and Jews in Ljubo Jandrić's novel "Jasenovac"

Posmatrajući Jandrićev roman kao svojevrsno svedočanstvo o zločinima nad Srbima i Jevrejima, počinjenim u koncentracionom logoru Jasenovac, u radu se bavimo genezom zla, mržnje i destrukcije. Takođe, fokus je usmeren na upotrebu dokumentarne i arhivske građe u romaneskne svrhe. Upravo iz tog razloga, tumačenje ćemo izvoditi interdisciplinarnim pristupom, konsultujući poznate ali i novije studije o ustaškim zločinima. Militantni rasizam i verska mržnja prema Srbima, Jevrejima i Romima, podsticani u okviru državnog aparata, negovani i praktikovani u redovima Katoličke crkve, proželi su sve pore društva ND Hrvatske i na koncu doživeli kulminaciju u strategijama ustaške nekropolitike koja je rezultirala totalnim genocidom. U radu smo, na primeru Jandrićevog romana, ukazali na etape razvoja ustaške ideologije i nekropolitičke prakse.Examining Jandrić's novel as a testimony about the crimes against the Serbs and the Jews, committed in the concentration camp Jasenovac, we deal with the genesis of evil, hatred, and destruction. Also, the focus of the paper is on the use of documentary and archival material. Precisely for that reason, we performed the interpretation with an interdisciplinary approach, consulting the well-known, but likewise recent studies on the Ustasha crimes as well. Militant racism and religious hatred towards the Serbs, the Jews, and the Roma, encouraged within the state apparatus, nurtured and practised in the ranks of the Catholic Church, permeated all the pores of the society of the Independent State of Croatia and finally culminated in the strategies of Ustasha necropolitics that resulted in total genocide. In the paper, through the example of Jandrić's novel, we point out the stages of development of the Ustasha ideology and necropolitical practice.Izdavanje ovog zbornika podržalo je Ministarstvo prosvete, nauke i tehnološkog razvoja Republike Srbije

Synthesis and structural properties of sodium cobalt oxide

Sodium transition-metal oxides with general formula NaxTMO2 (TM = Co, Mn, Ni, etc.) have attracted a lot of interest in the battery community due to low cost of sodium in contrast to lithium. Sodium cobalt oxide is the most attractive of them for cathode application because of its conductive, thermic and magnetic characteristics. In this study, sodium cobalt oxide, NaxCoO2 , was synthesized by simple method which involves solid state reaction in air, at temperature of 900 ºC; starting materials were Na2CO3 and Co3O4 in stoichiometric amounts. Additionally, fluorination of the synthesized sodium cobalt oxide was carried out in vacuum at 200ºC; NH4HF2 was used as a fluorine source. Then, structural and microstructural properties of the obtained powders were examined

Structural and magnetic properties of Y1-xYbxF3 solid solution

In this work, the polycrystalline samples Y1-xYbxF3 (x = 0.01, 0.05, 0.1, 0.25, 0.5, 0.75 and 1) were synthesized and characterized by X-ray powder diffraction and magnetic measurements. In the first stage of synthesis, mixed sesquioxides (Y1-xYbx)2O3 were obtained by ceramic technology. In the second stage, obtained mixed sesquioxides were treated with an excess of ammonium hydrogen fluoride in air at 170 °C for 20 h. In the third and last stage, Y1-xYbxF3 samples were obtained by heating the product from the second stage of synthesis at 500 °C for 3 h in an inert atmosphere. The X-ray diffraction revealed that the crystal structure of the Y1-xYbxF3 solid solution is orthorhombic (YF3 structural type). The structure refinements were done by the Rietveld full-profile method within Pnma space group. Magnetic susceptibility measurements of all samples were done in a temperature range 2-300 K by SQUID magnetometer. The relation between magnetic and structural properties was discussed

Influence of Mechanical Activation on the Constituents of the MgO-Al2O3-SiO2-TiO2 System

Cordierite, 2MgO2Al2O35SiO2, is a very attractive high-temperature ceramic material, due to its outstanding electrical characteristics, such as the low temperature expansion coefficient, low dielectric constant and good mechanical properties. In order to accelerate the process of sintering, 5.00 mass% TiO2 has been added to the starting mixtures. The mechanical activation of the starting mixtures was performed in a high energy ball mill during 0-80 minutes. The particle size analysis (PSA) was employed in order to determine the changes in the particle size of the mechanically treated powders. The phase composition of the starting powders was analyzed by the X-ray diffraction method. XRD showed decrease in peaks intensities and no new phases. Furthermore, differential thermal analysis (DTA) was used in order to determine characteristic temperatures within the system during heating. Based on the obtained DTA results, it was established that mechanical activation has some influence on temperatures of phase transitions

Characterization of mechanically activated ZnO powder

Materials based on ZnO structure have more frequently application as fillers in polymer ceramics nanocompozites. Performances of these materials depends on fillers morphology, surfaces texture and particles size. According to this, in this paper, the authors investigated the influence of mechanical activation of ZnO powder on crystal and micro structure. Commercially available ZnO powder was activated in a planetary ball mill for 2, 5, 10 and 30 minutes. Characterization of such obtained powders was performed using XRD, SEM and Raman spectroscopy. XRD patterns indicated at lowering of peak intensities along with its broadening wich is realted to partical fragmentation and amorphyzation. Micrographs show irregularly shaped particles at the beginning and with prolonged milling time, particles gained uniformed distibution, while after 30 minutes of activation agglomerates started forming. The results we got by investigation of dynamical structure by Raman spectroscopy are in correlation with the other results of structures analysis. Results presented here enable further optimization of, polymer nanocompozite based on ZnO and PVDF, making process

Combined magnetic and structural characterization of hidrothermal bismuth ferrite (BiFeO3) nanoparticles

Bismuth ferrite (BiFeO3) was synthesized by hydrothermal method. The crystal and magnetic structures of BiFeO3 have been studied by means of X-ray diffraction and neutron powder diffraction at ambient temperature. Microstructure was analysed by scanning electron microscopy. Quantitative phase analysis by the Rietveld method was conducted and crystallite sizes of 27 nm were determined from the XRD line broadening. The magnetic structure of BiFeO3 is described by the G-type antiferromagnetic order with magnetic peak located at 4.6 Å and a noticeable magnetic contribution to a reflection located at 2.4 Å in the diffraction pattern. The values of the ordered magnetic moment of Fe ions μFe=3.8(1) μB, obtained at ambient conditions, are consistent with those determined earlier. The magnetic moments in the crystal plane z = const are arranged in parallel, changing the direction from [100] to [ 110 ] when moving from one to the other z = const plane. © 2018 Authors. Published by the International Institute for the Science of Sintering

Synthesis, structural and magnetic properties of Y1-xYbxF3 solid solution

Many works devoted to obtaining nanodispersed BaTiO3 powder modified with different dopants for suitable properties providing. In particular, recently considerable attention has been given to obtaining modified nanopowders BaTiO3 possessing relaxor behavior order to ensure reliable work of dielectrics. Generally, Ca,Zr,Mn, ,Pb and rare earth elements such as Nb,Y adds order to provide stress, inhibit grain growth and provide Pinching effect, and hence to increase dielectrics relaxor behavior. However, there is still an issue associated with obtaining satisfactory stoichiometry of the obtained powder. From this viewpoint Ca,Zr-doped BaTiO3 were prepared with co-precipitation method via multiligand complexes formation and influence of the precursor type on Ca,Zr-doped BaTiO3 stoichiometry were investigated. Their stoichiometry, crystal structure was examined in order to determine preferential solubility site of Ca,Zr ions in perovskite structure. Stoichiometry Ca,Zr-modified BaTiO3 will be evaluated considering different precursor type. X-ray, IR spectroscopy and X-ray fluorescence analysis were carried out to obtain the knowledge on the occupation site in the Ba1-xСaxTi1-yZryO3 perovskite structure. These results proved influence complex formation on Ca,Zr-modified BaTiO3 stoichiometry

Synthesis and structural properties of sodium cobalt oxide

Sodium transition-metal oxides with general formula NaxTMO2 (TM = Co, Mn, Ni, etc.) have attracted a lot of interest in the battery community due to low cost of sodium in contrast to lithium. Sodium cobalt oxide is the most attractive of them for cathode application because of its conductive, thermic and magnetic characteristics. In this study, sodium cobalt oxide, NaxCoO2 , was synthesized by simple method which involves solid state reaction in air, at temperature of 900 ºC; starting materials were Na2CO3 and Co3O4 in stoichiometric amounts. Additionally, fluorination of the synthesized sodium cobalt oxide was carried out in vacuum at 200ºC; NH4HF2 was used as a fluorine source. Then, structural and microstructural properties of the obtained powders were examined