This review article focuses on the sol-gel preparation of high temperature superconducting oxides wherein different classes of gel technologies were utilized. These involve: 1) the sol-gel route based upon hydrolysis-condensation of metal-alkoxides, 2) the gelation route based upon concentration of aqueous solutions involving metal-chelates, often called as “chelate gel” or “amorphous chelate” route, and 3) the organic polymeric gel route. This paper reviews the current status of these sol-gel processes, and illustrates the underlying chemistry involved in each sol-gel technology. It is demonstrated that the chemical homogeneity of the gel is often disturbed by the differences in the chemistries of the cations. Prior to gelation the starting precursor solution containing various forms of metal-complexes must be chemically modified to overcome this problem. Illustration of a variety of strategies for success in obtaining a homogeneous multicomponent gel with no precipitation is focal point of this review article.

Invited review “sol-gel” preparation of high temperature superconducting oxides

Disclosed is a method for producing fluorinated organic compounds, including petnafluoropropenes, which preferably comprises converting at least one compound of formula (I): CFnXmCFaXbCH2X (I) to at least one compound of formula (II) CF3CF═CHF (II) where each X is independently Cl, I or Br; n is 2 or 3; m is 0 or 1, a is 1 or 2, b is 0 or 1, m+n=3 and a+b=2.

Method For Producing Fluorinated Organic Compounds

Piezoelectric materials have been integrated with silicon microelectromechanical systems (MEMS) in both microsensor and microactuator applications. Thin-film materials selection and processing routes are reviewed. Some recent and emerging applications of piezoelectric MEMS are presented including acoustic emission microsensors, vibration monitors, molecular recognition biosensors, precision positioners, micropumps, and linear stepper motors.

Processing and characterization of piezoelectric materials and integration into microelectromechanical systems

This account focuses on the synthesis and characteristics of ceramics prepared by the Pechini-type in-situ polymerizable complex (IPC) method The current status of the IPC method is reviewed, and the principle and underlying chemistry of the IPC method is illustrated with a special emphasis on its intrinsic advantage over other solution-based technologies The method has the ability to prepare complex multicomponent oxides with good homogeneity through mixing at the molecular level The importance of “polymerization” itself in the IPC route is demonstrated by comparing with the non-polymerizable so-called amorphous citrate method, which affords less compositional homogeneity The use of heterometallic complexes in the IPC processing is shown to be one of the most promising techniques to synthesize ceramics with exceptionally good homogeneity It is one function of this account to describe how Raman and 13C NMR spectroscopies can be effectively used for characterizing precursors in the IPC processing Fin

Synthesis and characteristics of complex multicomponent oxides prepared by polymer complex method

A location tagged data provision and display system. A personal communication device (PCD) with electromagnetic communication capability has a GPS receiver and a display. The PCD requests maps and location tagged data from data providers and other for display on the PCD. The data providers respond to requests by using searching and sorting schemes to interrogate data bases and then automatically transmitting data responsive to the requests to the requesting PCD.

Positional camera and gps data interchange device

In the investigation of the sol-gel processing, it has been noted that this process provides a means of producing high-purity homogeneous material of the desired stoichiometric composition such as metal alkoxide complexes. Lithium niobate ceramics were produced by reaction of equimolar quantities of lithium ethoxide and niobium ethoxide. Evaporation of the ethanolic solution at room temperature produced crystals that were transparent and 2-5 mm in length. A complete crystallographic study of these crystals was carried out, and the results are presented herein. 12 refs., 2 figs.

Crystal structure of lithium niobium ethoxide (LiNb(OCH2CH3)6: a precursor for lithium niobate ceramics

A process is disclosed for forming a coating on a substrate. A metal layer is placed onto the substrate either by plasma spray deposition or by applying a metal foil and then subjecting it to rapid omnidirectional compaction. The metal is then reacted with a source of carbon, nitrogen, or a combination thereof, such that a metal carbide, nitride, or carbonitride layer is formed. The product is a densified coated ceramic composition.

Rapid omnidirectional compaction process for producing metal nitride, carbide, or carbonitride coating on ceramic substrate

This invention is a method comprising providing a substrate, forming a first layer on the substrate, wherein the first layer has a dielectric constant of less than 3.0 and comprises an organic polymer, applying an organosilicate resin over the first layer, removing a portion of the organosilicate resin to expose a portion of the first layer, and removing the exposed portions of the first layer. The invention is also an integrated circuit article comprising an active substrate containing transistors and an electrical interconnect structure containing a pattern of metal lines separated, at least partially, by layers or regions of an organic polymeric material having a dielectric constant of less than 3.0 and further comprising a layer of an organosilicate resin above at least one layer of the organic polymer material.

Organosilicate resins as hardmasks for organic polymer dielectrics in fabrication of microelectronic devices

Le complexe WS 4 [Rh(COD)] 2 est prepare rapidement par reaction de quantites stœchiometriques de (Ph 4 P) 2 WS 4 avec [Rh(COD)Cl] 2 dans l'acetonitrile. Les complexes [(RC 5 H 4 )Ru(PPh 3 )] 2 MS 4 sont obtenus par reaction de (RC 5 H 4 )Ru(PPh 3 ) 2 Cl avec (Ph 4 P) 2 MS 4 . Structures moleculaires

Organometallic derivatives of the tetrathiometallates. Syntheses, structures, and reactions of MS4[Rh(COD)]2 and MS4[(C5H5)Ru(PPh3)]2 (M = Mo, W)

Synthetic routes to tetrathiometalate complexes of rhodium, iridium, palladium, and platinum are described. Acetonitrile solutions of WS/sub 4//sup 2 -/ reacted with (Rh(diene)Cl)/sub 2/ (where diene = 1,5-cyclooctadiene (COD) or norbornadiene (NBD)), (Ir(COD)Cl)/sub 2/, ((/eta//sup 5/-C/sub 5/Me/sub 5/)RhCl/sub 2/)/sub 2/, and (Pd(allyl)Cl)/sub 2/ to give good yields of ..mu..-WS/sub 4/ complexes (Rh(diene))/sub 2/WS/sub 4/, (Ir(COD))/sub 2/WS/sub 4/, ((/eta//sup 5/-C/sub 5/Me/sub 5/)RhCl)/sub 2/WS/sub 4/, and ((allyl)Pd)/sub 2/, respectively. (COD)PtCl/sub 2/ reacted with MS/sub 4//sup 2 -/ to give (COD)PtMS/sub 4/, M = Mo, W. The later complexes react further with PPh/sub 3/ or WS/sub 4//sup 2 -/ to give (PPh/sub 3/)/sub 2/PtMS/sub 4/ and Pt(WS/sub 4/)/sub 2//sup 2 -/, respectively. (Rh(COD))/sub 2/WS/sub 4/ reacted with t-BuNC to give (Rh(t-BuNC)/sub 2/)/sub 2/WS/sub 4/. RhCl/sub 3/ x 3H/sub 2/O react with WS/sub 4//sup 2 -/ to give the octahedral complexes M(WS/sub 4/)/sub 3//sup 3 -/ isolated as their Et/sub 4/N/sup =/ salts. The /sup 183/W NMR spectrum of (Et/sub 4/N)/sub 3/(Rh(WS/sub 4/)/sub 3/) showed a doublet with J(/sup 183/W,/sup 103/Rh) = 4.8 Hz. Thermal gravimetric analyses of (Rh(COD))/sub w/WS/sub 4/ and (COD)PtWS/sub 4/ indicate that loss of organic coligands and stoichiometric amounts of sulfur occur at moderate temperatures. The compound ((/eta//sup 5/-C/sub 5/Me/submore » 5/)RhCl)/sub 2/WS/sub 4/ x CHCl/sub 3/ crystallizes in the orthorhombic space group P2/sub 1/2/sub 1/2/sub 1/ with a = 13.179 (2) /angstrom/, b = 28.725 (7) /angstrom/, c = 8.258 (2) /angstrom/, V = 3126 (2) /angstrom//sup 3/, and Z = 4 and was refined to R = 0.052 and R/sub w/ = 0.059.« less

Kevin E. Howard

Papers

Crystal structure of lithium niobium ethoxide (LiNb(OCH2CH3)6: a precursor for lithium niobate ceramics

Rapid omnidirectional compaction process for producing metal nitride, carbide, or carbonitride coating on ceramic substrate

Organosilicate resins as hardmasks for organic polymer dielectrics in fabrication of microelectronic devices

Organometallic derivatives of the tetrathiometallates. Syntheses, structures, and reactions of MS4[Rh(COD)]2 and MS4[(C5H5)Ru(PPh3)]2 (M = Mo, W)

Tetrathiometalate Complexes of Rhodium, Iridium, Palladium, and Platinum. Structures of [(C5Me5)RhCl]2WS4 and [(C3H5)Pd]2WS4