Download or read book Synthesis of Tungsten Nitrene Complexes as Precursors for Tungsten Nitride written by and published by . This book was released on 1994 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical vapor deposition using organometallic precursors (MOCVD) provides a method for the preparation of thin films. Low valent tungsten nitrene complexes were synthesized as potential precursors to tungsten nitride (WN(x)), a material used in diffusion barriers for Si or GaAs semiconductor devices. The original target precursors for MOCVD of WN(x) were the carbonyl-containing complexes (CO)(5-n)(PR3)(n)W-NR, where R is an alkyl or aryl group. Later synthetic work involved the tungsten (IV) imido (or nitrene) complexes (CO) 2I2LW(triple bonds)NPh, which were prepared by oxidation of the zwitterionic species (CO)5WNPhNPhC(OMe)Ph with one equivalent of I2 followed by addition of a the coordinating species L L=THF, pyridine, PMe3, P(OMe)3.
Download or read book Study of Tungsten IV and Tungsten VI Imido Complexes written by Corey B. Wilder and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of tungsten guanidinate and amidinate complexes were synthesized to serve as precursors for the metal-organic chemical vapor deposition of tungsten nitride. Compounds were characterized by 1H and 13C NMR. In addition, mass spectrometry was used for characterization as well as to give insight into precursor fragmentation tendencies. Crystallography experiments were also conducted to investigate the bonding motifs present in the series of compounds.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research in Progress written by and published by . This book was released on 1992 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Novel Group VI Metal Mo W Nitride and Oxide Compounds written by Zhihong Zhang and published by . This book was released on 1997 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Binary Group VI metal nitrides are characterized by thermodynamic instability towards dissociation to N2 and the N-saturated elements at high temperature. Our investigations into the preparation of tungsten nitrides have involved the synthesis of molecular precursors, and their conversion to tungsten nitrides at relatively low temperatures. Two interesting molecular precursors, [WNCl3·NCCH3]4 and WN(N3)3·xNCCH3, have been prepared and characterized. The Molecular structure of [WNCl3·NCCH3]4 consists of a W4N4 tetrameric core with multiple and single WN bonds arranged in an alternating fashion.
Download or read book Synthesis and Characterization of Novel Group VI Metal Mo W Nitride and Oxide Compounds written by and published by . This book was released on 1998 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigations into the preparation of tungsten nitrides have involved the synthesis of molecular precursors, and their conversion to tungsten nitrides at relatively low temperatures. Two interesting molecular precursors, [WNCl3·NCCH3]4 and WN(N3)3·xNCCH3, have been prepared and characterized. The molecular structure of the first consists of a W4N4 tetrameric core with multiple and single W-N bonds arranged in an alternating fashion. Three new solid state phases, amorphous W3N5, cubic WN, and W2N2(C2N2), have been discovered by solid state and chemical vapor transport reactions. The structures have been investigated. A systematic study in the Ln2O3-MoO3-Mo (Ln = La, Ce, Pr, Nd, Sm) system has been explored to better understand LnMoO14. The study has shown that the sizes of the rare-earth cations affect the formation of these phases. Larger cations (La, Ce, and Pr) aid in the formation of trans-Mo bicapped octahedra, and the smaller cations (Nd, Sm) only stabilize the cis-Mo8 bicapped octahedra. Magnetic susceptibility measurements have indicated that no effective moment contribution arises from the Mo8 metal clusters, even though the cis-Mo8 cluster in LnMo8O14, containing all cis-Mo8 octahedra, apparently contains an odd number of electrons (23). Electrical resistivity measurements and electronic structure calculations have shown that the LnMo8O14 compounds containing cis-Mo8 clusters are metallic, and the LnMo8O14 compounds containing a 1:1 ratio of cis- to trans-Mo8 clusters are semiconducting.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Reactivity of Tungsten Imido Complexes from a Zwitterionic Tungsten Zero Amido Precursor written by Scott Taylor Massey and published by . This book was released on 1995 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1995-09 with total page 1436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stabilization and Reactivity of Zero valent Tungsten Nitrene Complexes written by Bruce A. Arndtsen and published by . This book was released on 1993 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tungsten IV Nitrene Complexes written by Li Luan and published by . This book was released on 1992 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Solid Phase Synthesis of Tungsten Isocyanide Complexes as Precursors to a Molecular Level Wire written by Richard Walter Hartmann and published by . This book was released on 2000 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Chemistry of Non Sag Tungsten written by L. Bartha and published by Elsevier. This book was released on 2013-10-22 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-sag (NS) tungsten is a dispersion-strengthened microalloy with elemental potassium, which is contained as microscopic bubbles in the tungsten lattice. Under working conditions in an incandescent lamp the potassium is a gas under high pressure. These gas bubbles essentially prevent the recrystallization of the tungsten wire and are responsible for the outstanding creep resistance of NS tungsten at the extremely high temperatures of a glowing lamp filament. More than 90% of NS tungsten is used for incandescent lamps. In addition, small amounts are used as defroster heating wires in automobile windshields and as heating wire coils for aluminium evaporation in metallization applications. The presented papers deal with the chemical reactions and the chemical compounds occurring along the path from tungsten raw materials to the final NS tungsten filament; a compendium of present knowledge on the different chemical aspects of NS tungsten manufacture is presented. It is composed of nine individual papers, each of them written by experts working in the field.
Download or read book The Synthesis and Reactivity of Tungsten VI Alkylidynes and Tungsten IV Complexes written by Mark L. Listemann and published by . This book was released on 1985 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synthesis and Characterization of Some Tungsten Nitrides and Reduced Molybdenum Oxides written by Clark Dale Carlson and published by . This book was released on 1989 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synthesis and Reactivity of Methylidyne and Hydride Complexes of Tungsten written by Steven J. Holmes and published by . This book was released on 1983 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Reactivity of Cyclopentadienyl Complexes of Tungsten in Its Higher Oxidation States written by Robert Clark Murray and published by . This book was released on 1985 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
