Download or read book Synthesis and Characterization of New Mixed metal Chalcogenides and Oxychalcogenides written by Theodore Dennis Brennan and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of New Low Dimensional Transition Metal Chalcogenides written by Steven Arthur Sunshine and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mixed Metal Chalcogenides written by Dr. Satishkumar V. Patil and published by Ashok Yakkaldevi. This book was released on 2020-12-10 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1.1 Introduction VIA group elements in the periodic table are known as chalcogens. Chalcogens are sometimes known as oxygen family. Oxygen (O), Sulphur (S), Selenium (Se) and Tellurium (Te) are the elements of chalcogens. The chalcogen term was first introduced by Wilhelm Bilts group around 1930 at the University of Honover, where it was proposed by a Scientist Werner Fischer [1]. Chalcogen is a Greek word which means ‘ore forming’. Chalcogen elements react with almost all elements in the periodic table to form stable compounds, which occurs in the earth crust and these are the ores of particular elements. So they are named as ‘ore formers’. Oxide, sulphite, selenide and telluride are insoluble in water. A Chalcogenide is the chemical compound consisting of at least one chalcogen ion and at least one more electropositive element. Chalcogenide term is more commonly reserved for sulfides, selenides, tellurides and not for oxides,
Download or read book New Transitional Metal Chalcogenides written by Douglas A. Keszler and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Properties of New Oxychalcogenide Materials written by David George Free and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1 gives a brief review of oxychalcogenide materials and their properties, particularly those with structures similar to systems discussed in the later chapters. Particular attention is paid to the structural and magnetic properties of La2O2Fe2OSe2-type materials, work on which is presented in chapters 3?5. These oxychalcogenides, along with ZrCuSiAs-related materials, are of interest due to their potentially interesting magnetic and conducting properties. In particular they are close relatives of the LaOFeAs superconductors. Chapter 2 describes the synthetic and analytical techniques used in this project. The theory behind the powder diffraction techniques used throughout is described, and information on specific methodology used in the data collections and analysis of this work is given. SQUID magnetometry is also discussed. Chapter 3 discusses the variable temperature structural and magnetic properties of La2O2Mn2OSe2 and Pr2O2Mn2OSe2, as well as those of the newly prepared material Ce2O2Mn2OSe2. These materials are observed to undergo a phase transition on cooling revealed by a change in the thermal expansion of the c cell parameter, and show evidence for the static disorder of oxide ions from the [Mn2O]2+ plane below this temperature. Pr2O2Mn2OSe2 is also shown to undergo a further transition on cooling below 36 K to an orthorhombic unit cell. Neutron diffraction data have also shown that the Mn2+ moments in these materials order with an AFM1 structure on cooling below ~180 K. Chapter 4 describes the study of both La2O2Fe2OS2 and La2O2Fe2OSe2 by variable temperature neutron powder diffraction. These materials have been demonstrated to order with an AFM3 structure on cooling below ~100 K, which is coincident with a subtle structural change observed in the thermal expansion of the a cell parameter. The unexpected adoption of the AFM3 magnetic structure is discussed in relation to structurally similar iron-based superconductors. Chapter 5 presents the synthesis of several new La2O2Fe2OSe2-type materials, and the magnetic structure of La2O2Co2OSe2. The stability range over which these materials form is discussed with respect to the size of the metal ions present. A comparison of the structural properties of all the A2O2M2OSe2 materials is given and the various magnetic structures they adopt discussed. Chapter 6 reports the synthesis of a new family of transition metal oxychalcogenides (? La2O2MnSe2). Their structure has been solved from laboratory X ray diffraction data, using a combination of charge-flipping and direct methods, and confirmed by neutron diffraction. Variable temperature structural properties are discussed and show these materials undergo a phase transition on cooling associated with ordering of transition metal ions. SQUID magnetometry and neutron powder diffraction have both demonstrated these materials order antiferromagnetically at low temperatures. Chapter 7 describes the synthesis of two new ZrCuSiAs-related transition metal containing oxychalcogenides: Ce2O2FeSe2 and La2O2ZnSe2. The structure solution of Ce2O2FeSe2 by charge-flipping is reported, alongside the determination of the magnetic structure from neutron powder diffraction data collected at 12 K. The variable temperature structural properties of La2O2ZnSe2 are also reported.
Download or read book Design Synthesis and Characterization of Novel Semiconducting Metal Chalcogenides with Multifunctional Properties written by and published by . This book was released on 2008 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal chalcogenides possess a wide range of interesting chemical and physical properties, including low-temperature superconductivity, semiconductivity, ionic conductivity, intercalation, and optical properties. To expand chalcogenides beyond their traditional applications, it is desirable to generate novel chalcogenide materials with multifunctionality for uses in the areas of catalysis, separation, ion exchange, and gas storage by modifying the framework architectures and tuning the chemical components. The primary focus of my Ph. D. study is to design and synthesize chalcogenide materials with new structures and interesting multifunctional properties. The large variety of chemical compositions and structures make it possible to tune the properties, such as band gap, luminescence, pore size, surface area, and thermal stability. Most of the synthesis has been carried out using solvothermal reactions refs in pyrex tube or teflon lined autoclaves. Novel three-dimensional (3D) microporous chalcogenides constructed on building units [M-Sn-Q]n- (M=Zn, Cd, Mn; Q=S, Se) have been obtained. Their structures have been characterized by both single crystal and powder X-ray diffraction methods. Optical diffuse reflectance experiments have indicated that these compounds are semiconductors with intermediate band gaps between 1.5~2.9eV. The successful doping/substitution of 5%~20% Mn and Se in the [Zn-Sn-S]n- structure allows systematic tuning of the band gap and optical properties of this semiconductor compound. All compounds show a high thermal stability over 400°C. Our studies also show that the guest molecules and cations residing in the open frameworks are exchangeable. Another novel two dimentional ion sulfide [Fe(en)3]·[Fe16S20]·en compound was synthesized as well. UV-Vis reflectance spectroscopy showed a very low absorption coefficient and small band gap ~0.5eV. Doping/substitution experiments with Co and Mn replacing Fe were carried out and the properties will be discussed. In summary, this work has provided examples of rational synthesis and property tuning of new functional materials with new structure types, and demonstrated structure-property correlation in metal chalcogenide based compounds. It has provided useful information for the future developments of material synthesis with desired multifunctionality.
Download or read book Synthesis and Characterization of New Lanthanide Chalcogenides written by Geng Bang Jin and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of New Chalcogenides with Tetrahedral Building Blocks written by Joonyeong Kim and published by . This book was released on 1999 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Structural Characterization of New Multinary Group 15 bismuth and Antimony Chalcogenides written by Sumohan Misra and published by . This book was released on 2004 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Structural and Spectroscopic Characterization of New Polychalcogenide Complexes of Indium and Thallium and Their Applicaton as Precursors to Solid State Materials written by Sandeep S. Dhingra and published by . This book was released on 1992 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Atomic Scale Derivatives and Clusters of Transition Metal Chalcogenides written by Tianyang Li and published by . This book was released on 2016 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overall, using titanium and vanadium chalcogenides as model systems, a solution phase synthesis methodology has been develop to create the original two dimensional organic intercalated transition metal chalcogenides, their atomic scale one dimensional chain derivatives and low temperature cluster and precursor phases. The electronic structures and the Li intercalation of the new phases are studied to understand the correlation of properties and structures, leading towards the design and discovery of more useful functional hybrid materials.
Download or read book Synthesis and Characterization of Copper Based Ternary Metal Chalcogenides written by Jose Javier Sanchez Rodriguez and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current climate crisis is a great concern to humankind due to the devastating effects of the consistent rise of anthropogenic greenhouse gases. A viable alternative to reducing greenhouse gas emissions is the development of solar harvesting technologies. The need to develop new semiconductor materials with more capacity to absorb light and convert it into electricity is rapidly growing. A promising class of materials for this purpose are copper-based ternary chalcogenides such as CuCrS2, CuSb1-xBixS2, and Cu3VS4.The synthesis and characterization of copper-based ternary chalcogenides nanocrystals (NCs) have gained popularity in the scientific community due to their novel, physical, chemical, optical, electronic, magnetic, and mechanical properties. NCs can be precursors to the next-generation nanoparticle-based thin film solar cells. This generation of thin film solar cells is advantageous in terms of the compounding benefits. Materials in the forms of NCs offer size, and morphology-dependent properties, high absorption coefficients, and tunable bandgaps. Nanoparticle-based thin film solar cells use very thin layers of material, lowering their production cost while making the systems flexible, more efficient, and compatible with new and existing infrastructure.This dissertation addresses several challenging issues and realizes the successful fabrication of novel CuCrS2, CuSb1-xBixS2 (x=1, 0.18), and Cu3VS4 NCs-based thin films. These systems were synthesized using two different thermal decomposition methods: heat-up (HU) and hot-injection (HI). This dissertation presents a detailed study involving the synthesis and characterization of the above-mentioned semiconductors by applying the developed nano-to-thin film approach. Their optical and electrical properties were explored, and their respective optical bandgaps were determined using UV-vis and electron energy loss spectroscopy (EELS). The ability of the fabricated thin films to generate a photocurrent under sunlight irradiation was explored, reporting their responsivities and current conversion efficiencies.
Download or read book Synthesis and Characterization of Metal Chalcogenide MQ2 nanoparticles written by Nicole Christin Zink and published by . This book was released on 2006 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low dimensional Transition Metal Chalcogenides written by Juliane Stahl and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synthesis and Characterization of a Number of Poorly Crystallized Group VIII Transition Metal Chalcogenides written by June D. Passaretti and published by . This book was released on 1981 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1992 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Earth Abundant and Nontoxic Metal Chalcogenides Produced Via Aerosol Spray Pyrolysis for Photovoltaic Applications written by Patrick John Davis and published by . This book was released on 2013 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel synthesis technique for the production of copper zinc tin sulfide (CZTS) nanocrystals has been developed using aerosol spray pyrolysis. CZTS is a quaternary semiconducting material that shows promise as a replacement to common semiconductors such as CdTe and CIGS for use in photovoltaic devices. CIGS is currently being commercialized in the photovoltaic industry, but rare and expensive indium and gallium components threaten its long term viability. CZTS looks to be one of the best alternatives to CIGS with all earth abundant and non-toxic materials and recent impressive gains in efficiency. A number of synthesis techniques have been thoroughly studied and detailed previously. In our novel approach, we synthesis single phase nanocrystals, starting with zinc, copper, and tin diethyldithiocarbamate precursors in a toluene solvent. The precursor solution is aerosolized using an ultrasonic nebulizer wherein the droplets are vacuumed through a tube furnace and nucleation occurs. We reproducibly synthesize kesterite, Cu2ZnSnS4, nanocrystals. This technique continuously converts the chemical precursor into high-purity nanopowder with a production rate of ~50 mg/hour for an un-optimized, lab-scale reactor. Using the same precursor chemistry, we have also been able to deposit high-quality CZTS thin films directly onto Mo-coated Swiss glass substrates using the aerosol spray pyrolysis technique. A thorough discussion of the current photovoltaic field, the processing parameters and challenges of nanocrystal and thin film production, and the experimental results will be presented. Characterization via Raman spectroscopy, EDS, XRD, TEM and XPS will be offered along with future recommendations and considerations.
