Download or read book Transition Metal Borides Synthesis Characterization and Superconducting Properties written by Mehmet Kayhan and published by . This book was released on 2013 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transition Metal Compounds written by Sajjad Haider and published by BoD – Books on Demand. This book was released on 2021-06-09 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores synthesis, structural changes, properties, and potential applications of transition metal (TM) compounds. Over three sections, chapters cover such topics as the synthesis of pentoxide vanadium (V2O5), the effect of TM compounds on structural, dielectric properties and high-temperature superconductors, and TM-doped nanocrystals (NCs).

Download or read book Synthesis Characterization and Physical Properties of Metal Borides written by Denis Fofanov and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Transition Metal Diborides written by Jimmy Thörnberg and published by Linköping University Electronic Press. This book was released on 2021-01-20 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is devoted towards physical vapor deposition (PVD) of thin films of transition-metal (TM) diborides, focused on the material system TiBx, Ti1-xAlxB2-y and CrBx. The metal diborides are a large family of compounds with both metallic and ceramic properties, due to its bonding nature being a mix of covalent and ionic bonds. Their characteristics include, e.g., good mechanical, electrical and thermal properties, while an improved oxidation and corrosion resistance are currently sought after. Furthermore, while the ideal composition of these diborides is TMB2, i.e. with a B to metal ratio of 2, the stoichiometry in the PVD deposited films typically diverges from this ratio. TiBx is often reported to be overstoichiometric, with x well above 2. One of the most known and commonly used member of the TM diboride family is TiBx, primarily used in hard-coating applications such as tools for machining Al. However, the material displays a fracture toughness and oxidation resistance that ideally needs to be improved. The films presented in this thesis were deposited by high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS). Using both methods facilitates an improved control of both microstructure and composition, and hence the materials properties. With HiPIMS, understoichiometric TiBx films were grown and it was shown that these films can match and even exceed the overstoichiometric counterpart, deposited with DCMS, in terms of mechanical properties. The hardness and fracture toughness for TiB1.43 films were measured at 43.9±0.9 GPa and 4.2±0.1 MPa√m, compared to TiB2.70 films at 37.7±0.8 GPa and 3.1±0.1 MPa√m. Furthermore, the understoichiometric films significantly improve the oxidation resistance. Air annealing of TiB1.43, TiB2.20, and TiB2.70 films at 400 °C showed an average oxidation rate of 2.9±1.5, 7.1±1.0, and 20.0±5.0 nm/h, respectively, explained by the microstructural difference between over- and understoichiometric material. In TiBx films where x > 2, there is a B-rich tissue phase in the grain boundaries which is suggested to enhance oxidation. The hydroscopic nature of B2O3 causes more rapid oxidation and evaporation thus providing an easy oxidation pathway in B-rich regions. However, understoichiometric films where x < 2 do not show any significant boundary phases. Instead, the B deficiency is presented as planar defects with Ti-rich stacking faults. Hence the absence of the B-rich tissue phase has strongly contributed to increasing the oxidation resistance. Oxidation resistance and mechanical properties were also investigated for understoichiometric Ti1-xAlxB2-y coatings with varying Ti:Al and B:M ratios, obtained from both HiPIMS and DCMS depositions. Al alloying of the TM diboride TiBx significantly enhances the oxidation resistance. However, incorporating too much Al is at the expense of the excellent hardness seen in the pure TiBx, going from 46.2±1.1 GPa to 22.6±1.1 GPa for Ti0.9Al0.1B1.3 and Ti0.3Al0.7B1.3, respectively. Hence, a reduction in the Al content is needed to retain the mechanical properties. The boundary phase in this material consists of a Ti1-xAlxB2-y tissue phase, rich in either Al or B depending on the x and y values. An improved oxidation resistance in Ti1-xAlxB2-y was seen with reduced Al and B content, proposed to be due to absence of tissue phase in the grain boundaries, in line with the observations for TiBx. The oxide scale thickness of Ti0.9Al0.1B1.3 and Ti0.9Al0.1B1.9 after air annealing at 600 °C for 10 h was measured to be 205 nm and 320 nm, respectively. Moreover, the trends indicate a reduced oxidation rate as the oxide scale grows thicker. A systematical study of DCMS deposited CrBx coatings, 1.90 ≤ x 2.08, was also performed, motivated by CrBx being a material of interest for providing potential corrosion resistance. All films, irrespectable of the deposition conditions, exhibited (001) texture, with epitaxial growth observed when increasing temperature from 500 °C to 900 °C. Higher density (5.2 g/cm3) and smoother surfaces was seen in films grown at lower pressure, 5 mTorr (0.67 Pa), compared to higher pressure, 20 mTorr (2.67 Pa), and was explained by less gas scattering leading to more energetic particles impinging on the surface. CrBx film composition show no apparent dependence on substrate temperature, and has a slight dependence on deposition pressure for the samples deposited at 900 °C, with reduced B content for increasing pressure. Overstoichiometric CrB2.08 films showed the presence of large B-rich inclusions, and B deficiency in CrB1.90 films presented as planar defects with Cr-rich stacking faults, similar to understoichiometric TiBx. The thorough investigations of all the systems in this thesis are aimed towards improving the understanding of the correlation between the thin film synthesis process and the resulting composition and microstructure, which in turn dictates the properties of thin films. A particular emphasis is put on control of composition. I den här avhandlingen fokuserar jag på beläggningar av tunna filmer, dvs. tunna lager av material som läggs på en yta för att ge ytan vissa specifika egenskaper. Jag genomför metodiska analyser av de filmer jag får från två olika beläggningsmetoder; ”high-power impulse magnetron sputtering” (HiPIMS) och den mer konventionella metoden ”directcurrent magnetron sputtering” (DCMS). Dessa metoder skiljer sig främst åt i antal parametrar man kan variera för att kontrollera processen som styr vilket material som bildas, där HiPIMS är den metod med flest parametrar. Anledningen till att HiPIMS inte har sett ett större användningsområde till dags dato är att det är en relativt ny process jämfört med DCMS, och på grund av den komplexitet som tillkommer när man utökar mängden tillväxtparametrar. För båda processerna är en grundläggande förståelse av både processen och materialet önskvärt för att få ett optimerat material, med specifika önskade egenskaper. Material i fokus i denna avhandling är TiBx, Ti1-xAlxB2-y och CrBx, även kallade övergångsmetall-diborider, där Ti står för titan, Al för aluminium, Cr för krom, B för bor, och x/y står för variabler i sammansättningen av materialet. Dessa diborider bär med sig unika egenskaper från respektive element och innehåller en blandning av kovalenta bindningar och jon-bindningar. Beroende på sammansättningen av atomer så kan vi se olika mekaniska, elektriska och termiska egenskaper samt olika grad av oxidering- och eroderings-resistans. TiBx är till exempel välkänt för sina tillämpningar inom skärande bearbetning, men har inte lika lovande egenskaper när det kommer till beständighet mot oxidering. Det här är delvis en konsekvens av att man idag kommersiellt använder sig främst av DCMS för tillväxt av dessa beläggningar, då denna metod typiskt genererar överstökiometriska tunna filmer av TiBx (x > 2), vilket i sin tur påverkar beständigheten mot oxidering negativt. Med hjälp av HiPIMS kan man kontrollera stökiometrin av filmen i större grad, och kan således generera understökiometrisk TiBx (x < 2) som jag visar på har bättre mekaniska egenskaper, bland annat högre hårdhet, bättre brottseghet och förbättrad beständighet mot oxidering, kontra den överstökiometriska motsvarigheten. Hur mikrostrukturen i överstökiometriska TiBx filmer ser ut är välkänt, där överflödigt B ansamlas i korngränserna och bilder en s.k. ”B-rik vävnadsfas”. Jag har påvisat hur motsvarande mikrostruktur ser ut för understökiometrisk TiBx filmer, något som fram tills nu varit okänt. I dessa faser saknas vävnadsfas i korngränserna, och istället hittas överskottet av Ti som plandefekter i de kolumnära TiB2-strukturerna i filmen. Jag visar på att avsaknaden av vävnadsfas i korngränserna tydligt förbättrar beständigheten mot oxidering, vilket troligtvis beror på att just korngränserna, och deras innehåll, agerar som en katalys for oxidering. På samma sätt undersöker jag hur materialsystemet Ti1-xAlxBy-2 beter sig med varierande Ti:Al förhållande och även B:M förhållande (bor till metall), i filmer skapade med både DCMS och HiPIMS. Målet med inkluderingen av Al är just att förbättra beständighet mot oxidering, och samtidigt bevara de åtråvärda mekaniska egenskaperna som filmer av TiBx har. Korngränserna i det här materialet består av en vävnadsfasblandning, rik på antingen Al eller B, beroende på förhållandet mellan x och y i Ti1- xAlxBy-2. Jag visar på att en reducering av denna vävnadsfas även här förbättrar beständigheten mot oxidering. Det påvisas genom att reducera Al- och B-innehållet i filmerna, vilket minskar vävnadsfasen i korngränserna, och således förbättras beständigheten mot oxidering. En systematisk undersökning av tunna filmer av CrBx, belagda med DCMS, har genomförts, då detta är ett materialsystem med potential för beständighet mot korrosion. Både lätt över- och understökiometriska filmer växtes, och fick sin mikrostruktur och lokala sammansättning undersökt. Alla filmer påvisade en (001) textur, med epitaxiell tillväxt när temperaturen ökade från 500 C° till 900 C°. Högre densitet (~5.2 g/cm3) och jämnare ytor sågs för filmer belagda vid lägre tryck, 5 mTorr (0.67 Pa), jämfört med högre tryck, 20 mTorr (2.67 Pa). Kompositionen för CrBx filmerna påvisade inte ett temperaturberoende, men visade ett marginellt beroende på beläggningstryck för prover växta vid 900 C°. Även observerat för understökiometriska CrB1.90 filmer är att underskottet av B presenteras som plandefekter med Cr-rika plan i de kolumnära CrB2- strukturerna i filmen, precis som i understökiometrisk TiBx. I överstökiometriska CrB2.08 filmer så visades stora inneslutningar av ansamlat B.

Download or read book Synthesis and Characterization of Novel Ternary Transition Metal Borides and New Synthesis Methods for Superhard ReB2 and Clathrate of Type 1 written by Burcu Uslu and published by . This book was released on 2010 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Superconductivity written by Paolo Mele and published by Springer Nature. This book was released on 2019-08-21 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with a comprehensive overview of the science of superconducting materials. It serves as a fundamental information source on the actual techniques and methodologies involved in superconducting materials growth, characterization and processing. This book includes coverage of several categories of medium and high-temperature superconducting materials: cuprate oxides, borides, and iron-based chalcogenides and pnictides. Provides a single-source reference on superconducting materials growth, characterization and processing; Bridges the gap between materials science and applications of superconductors; Discusses several categories of superconducting materials such as cuprate oxides, borides, and iron-based chalcogenides and pnictides; Covers synthesis, characterization, and processing of superconducting materials, as well as the nanoengineering approach to tailor the properties of the used materials at the nanoscale level.

Download or read book Groups IV V and VI Transition Metals and Compounds written by T. F. Connolly and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: responsibility.) To Betty Edwards and Emily Copenhaver my thanks for what must have seemed endless typing, retyping and correcting of these bibliographies over a span of years. Availability of Documents U. S. Government contractor reports, usually identified by an alpha-numeric report number, can be purchased from National Technical Information Service U. S. Department of Commerce Springfield, Virginia 22151 and, often, on request from the issuing installation. USAEC reports are also available from International Atomic Energy Agency Kaerntnerring A 1010 Vienna, Austria National Lending Library Boston Spa England Monographs and reports of the National Bureau of Standards are for sale by Superintendent of Documents U. S. Government Printing Office Washington, D. C. 20402 Theses, listed as Dissertation Abstracts + number, are available in North or South America from University Microfilms Dissertation Copies P. O. Box 1764 Ann Arbor, Michigan 48106 and elsewhere from University Microfilms, Ltd. St. John's Road Tylers Green Penn, Buckinghamshire England Other Information Centers and New Journals New journals Information centers Field and and other sources serials Ultra purification 4, 8, 11, 13, 15, 16,19, 20, 9,11,15, 24, 31, 32 and 21, 28, 30, 32, 33, 42, 58, 59 crystal growth ix Preface Field Information centers New journals and and other -sources serials Characterization Miscellaneous 3,4, 8, 11, 13, 16, 19, 20, 1,3,4,8,11,15,17, 21, 26, 28, 30, 31, 32, 33, 35, 24, 25, 28, 29, 30, 31, 37, 38, 39, 40, 42, 46, 53, 56, 32 58, 60, 61, 62

Download or read book Synthesis Characterization and Magnetic Properties of Some Transition Metal Diorganophosphinate and Dimethylarsinate Complexes written by Shihua Xia and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Superconducting Materials written by Yassine Slimani and published by Springer Nature. This book was released on 2022-05-03 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an overview of the science of superconducting materials. It covers the fundamentals and theories of superconductivity. Subjects of special interest involving mechanisms of high temperature superconductors, tunneling, transport properties, magnetic properties, critical states, vortex dynamics, etc. are present in the book. It assists as a fundamental resource on the developed methodologies and techniques involved in the synthesis, processing, and characterization of superconducting materials. The book covers numerous classes of superconducting materials including fullerenes, borides, pnictides or iron-based chalcogen superconductors ides, alloys and cuprate oxides. Their crystal structures and properties are described. Thereafter, the book focuses on the progress of the applications of superconducting materials into superconducting magnets, fusion reactors, and accelerators and other superconducting magnets. The applications also cover recent progress in superconducting wires, power generators, powerful energy storage devices, sensitive magnetometers, RF and microwave filters, fast fault current limiters, fast digital circuits, transport vehicles, and medical applications.

Download or read book Synthesis Characterization and Magnetic Properties of Some Transition Metal Diorganophosphinate and Dimethylarsinate Complexes written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook on Synthesis Strategies for Advanced Materials written by A. K. Tyagi and published by Springer Nature. This book was released on 2021-10-22 with total page 922 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents state-of-the-art coverage of synthesis of advanced functional materials. Unconventional synthetic routes play an important role in the synthesis of advanced materials as many new materials are metastable and cannot be synthesized by conventional methods. This book presents various synthesis methods such as conventional solid-state method, combustion method, a range of soft chemical methods, template synthesis, molecular precursor method, microwave synthesis, sono-chemical method and high-pressure synthesis. It provides a comprehensive overview of synthesis methods and covers a variety of materials, including ceramics, films, glass, carbon-based, and metallic materials. Many techniques for processing and surface functionalization are also discussed. Several engineering aspects of materials synthesis are also included. The contents of this book are useful for researchers and professionals working in the areas of materials and chemistry.

Download or read book Synthesis Characterization and Reactiviity of Transition Metal Boroalkoxide Complexes written by Aaron B. Frederick and published by . This book was released on 1994 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976-05 with total page 912 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Two Dimensional Transition Metal Dichalcogenides written by Narayanasamy Sabari Arul and published by Springer. This book was released on 2019-07-30 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents advanced synthesis techniques adopted to fabricate two-dimensional (2D) transition metal dichalcogenides (TMDs) materials with its enhanced properties towards their utilization in various applications such as, energy storage devices, photovoltaics, electrocatalysis, electronic devices, photocatalysts, sensing and biomedical applications. It provides detailed coverage on everything from the synthesis and properties to the applications and future prospects of research in 2D TMD nanomaterials.

Download or read book Synthesis Characterization and Properties of 3d Transition Metal Substituted Polyoxotungstates and Polyoxo noble metalates written by Yixian Xiang and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis Characterization and Computational Studies of Unsaturated Transition Metal Complexes written by Lori Anne Watson and published by . This book was released on 2004 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Low Temperature Synthesis Routes to Intermetallic Superconductors written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past few years, our group has gained expertise at developing low-temperature solution-based synthetic pathways to complex nanoscale solids, with particular emphasis on nanocrystalline intermetallic compounds. Our synthetic capabilities are providing tools to reproducibly generate intermetallic nanostructures with simultaneous control over crystal structure, composition, and morphology. This DOE-funded project aims to expand these capabilities to intermetallic superconductors. This could represent an important addition to the tools that are available for the synthesis and processing of intermetallic superconductors, which traditionally utilize high-temperature, high-pressure, thin film, or gas-phase vacuum deposition methods. Our current knowledge of intermetallic superconductors suggests that significant enhancements could result from the inherent benefits of low-temperature solution synthesis, e.g. metastable phase formation, control over nanoscale morphology to facilitate size-dependent property studies, robust and inexpensive processability, low-temperature annealing and consolidation, and impurity incorporation (for doping, stoichiometry control, flux pinning, and improving the critical fields). Our focus is on understanding the superconducting properties as a function of synthetic route, crystal structure, crystallite size, and morphology, and developing the synthetic tools necessary to accomplish this. This research program can currently be divided into two classes of superconducting materials: intermetallics (transition metal/post transition metal) and metal carbides/borides. Both involve the development and exploitation of low-temperature synthesis routes followed by detailed characterization of structures and properties, with the goal of understanding how the synthetic pathways influence key superconducting properties of selected target materials. Because of the low-temperature methods used to synthesize them and the nanocrystalline morphologies of many of the products, the superconductors and their nanocrystalline precursors are potentially amenable to inexpensive and large-scale solution-based processing into wires, coatings, films, and templated or patterned structures with nanoscale and microscale features. Also, because of the new synthetic variables that play a key role in the low-temperature formation of intermetallics, the possibility exists to discover new superconductors.