Preparation of Linear π-Conjugated Coordination Polymers Having Ruthenium(II) Complex in the Main Chain

Soluble -conjugated coordination polymers having a ruthenium(II) complex in the main chain were prepared from a soluble metal complex monomer and a bridging ligand via coordination. Refluxing of an ethanol-water suspension containing (4,4-dinonyl-2,2-bipyridyl)Ru(III) with 2,3-bis(2-pyridyl)pyrazine gave the coordination polymer. The resulting polymer was soluble in common organic solvents. The structure was confirmed by uv/vis spectra and gpc analysis.     

Preparation of nickel and Ni-Zn ferrite films by thermal decomposition of metal acetylacetonates

Nickel and Ni-Zn ferrite (Ni_1–x Zn _x Fe₂O₄) films were prepared on various substrates (quartz glass, MgO single crystal, etc.) by thermal decomposition of metal acetylacetonates (Ni (acac)₂ · 2H₂O, Zn (acac)₂ · 2H₂O and Fe (acac)₃). Typical decomposition and heat treatment conditions for obtaining a single phase of NiFe₂O₄ film were as follows: evaporation temperature of Ni-Fe complexes: 230°C, the mole concentration of Fe (acac)₃,R (%) = Fe (acac)₃/(Fe (acac)₃ + Ni (acac)₂ · 2H₂O) = 33, substrate temperature: 330 to 550° C, and heat treatment of the as-grown film: 800 to 1000° C, 1 h. Ni_1–x Zn _x Fe₂O₄ films were obtained by controlling the compositionR in Ni-Fe complexes and the evaporation temperature of Zn (acac)₂ · 2H₂O. The Ni-Zn ferrite film at the compositionx = 0.37 (Ni_0.63Zn_0.37Fe₂O₄) gave the maximum saturation magnetization _s = 60 emu g^–1 and the coercive forceHc 25 Oe. These films showed a magnetic anisotropy which makes the magnetization easy parallel to film surface.     

High temperature and pressure preparation and properties of iron carbides Fe7C3 and Fe3C

The formation regions of Fe₇C₃ and Fe₃C were determined at high temperature and high pressure in the iron-graphite system. Fe₇C₃ formed at relatively higher pressures and Fe₃C at lower pressures. Both Fe₇C₃ and Fe₃C were isolated from coexisting excess carbon powders by a magnetic method. Fe₇C₃ had a Curie point of 250° C and a saturation magnetization of 120 emu g^–1 at room temperature and Fe₃C had those of 210° C and 125 emu g^–1. Fe₇C₃ decomposed to Fe₃C and carbon at 600° C, but to -Fe and carbon at 700° C at atmospheric pressure, and Fe₃C to -Fe and carbon at 700° C. The substitution of other metals (Cr, Mo and W) for iron in these carbides leads to changes in the thermal stabilities and the magnetic properties.     

Synthesis of barium hexaferrite for magnetic recording media using the KCl flux system

Individual and fine crystals of barium hexaferrite were prepared by a modified flux method using the KCI flux system. Co²⁺-Ti⁴⁺-substituted barium hexaferrite with a homogeneous composition was synthesized at 950° C for 5 h or at 1000° C for 1 h from a mixture of BaCO₃, Fe₂O₃, CoO and TiO₂ with 30 wt% KCI added. Laboratory-prepared fine Fe₂O₃, was preferred because it gave ferrite particles with diameters of 0.2 to 0.4m. Magnetic properties were controlled by the Co-Ti content in hexaferrite crystals. Coercive force and Curie temperature decreased with the degree of Co-Ti substitution with saturation magnetization held at high value. The present process, from which individual and fine barium hexaferrite crystals can be prepared by using the KCI flux system, is recommended as a means of mass-production of ferrite powders with controlled magnetic properties for use in magnetic recording media.     

Oxide-dispersed titanium alloys Ti-Y prepared with the rotating electrode process

This work deals with an evaluation of the range of cooling rates during solidification necessary to obtain rare earth oxide-dispersed titanium alloys, which constitute a potentially interesting alloy system for high temperature use, due to the thermodynamic stability of rare earth oxides in titanium. The results of the microstructural studies on binary Ti-Y alloy powders prepared by the rotating electrode process show that it is possible to obtain e fine and homogeneous dispersion of yttrium oxide Y₂O₃ in a titanium maul with relatively moderate cooling rates ( 10⁴ K sec^–1). The results also indicate that the stability of the dispersion is excellent during hot consolidation but only in the phase temperature region (< 882.5° C). The preliminary mechanical teas performed on consolidated products show u substantial increase in 0.2% Woof stress (about 100 M Pa) up to 55O° C with respect to unalloyed titanium of commercial purity. Above 550° Q this strength increment becomes negligible or disappears. These results imply that the oxide dispersion loses its hardening effect at high temperatures, probably due to the increasing importance of grain-boundary sliding.     

Synthesis of hydroboration copolymer of TCNQ and formation of polymer charge transfer complex therefrom

Summary Novel TCNQ copolymers were prepared by hydroboration copolymerization of TCNQ with mesitylborane. The polymers obtained exhibited characteristics as a new class of polymer electron acceptors. When these polymers were treated with p-phenylenediamine at 80°C – 140°C in diglyme solutions, charge transfer complex formation was observed in UV-vis spectra. Hydroboration polymerization of p-, m-dicyanotetrafluorobenzene also proceeded to give the corresponding polymer electron acceptors. Received: 29 September 1998/Revised version: 17 November 1998/Accepted: 24 November 1998     

Effect of substituent groups for formation of organic-metal hybrid nanowires by charge-transfer of tetrathiafulvalene derivatives with metal ion

Effect of substituent groups on a tetrathiafulvalene (TTF) unit for formation of organic-metal hybrid nanowires was studied. Depend on the substituent groups, the nanowires were obtained as a precipitate just by mixing TTF derivatives and HAuCl₄ in CH₃CN solution at room temperature via electron transfer reaction between the TTF derivatives and a gold ion. To precede favorably hybrid nanowire formation, increase planarity and introduction of strong interaction on the TTF derivatives are required.     

An x-ray photo-electron spectroscopy study of the passivity of amorphous Fe-Mo alloys

The increase in molybdenum content in amorphous FeMoPC alloys facilitates the passivation in 1 N HCl in contrast to crystalline iron base alloys without chromium. An attempt was made to clarify the effect of molybdenum through the composition of surface film analyzed by XPS. The passive film consists mainly of ferric oxy-hydroxide, while a large amount of hexavalent molybdenum species is found in the surface film formed in the active region. The effect of molybdenum is interpreted as follows: the active dissolution necessary for proceeding the passive film formation leads to the precipitation of hexavalent molybdenum species on the alloy surface and as a result, the active dissolution is stifled. This fact leads to the passivation with the aid of iron ions which are already accumulated in the alloy/solution interface during the active dissolution.     

The Second Generation of the Laboratory Information System and the Laboratory Automation System in Osaka City University Hospital

The first total clinical laboratory system (TCLA) in the Osaka City University Hospital was introduced in 1993. After six years of operation, it was recently replaced by a new system. The goals of this replacement were as follows: 1. Improve the analytical performance. 2. Make the system operate more efficiently. 3. Improve the quality of laboratory analyses. We successfully reduced the labor required to operate the laboratory; made the laboratory reports quicker; reduced the number of retraction and revalidation of the results; and minimized the system downtime.