Showing papers on "Graphene oxide paper published in 1991"

Conformation of graphite oxide membranes in solution.

Abstract: We report an experimental study of polymerized membranes using graphite oxide (GO) suspension. Dry samples of GO are analyzed using electron microscopy and electron diffraction. They are found to be composed of thin solid membranes. The conformation of these membranes in solution is investigated using light scattering and is found to be fractal.

Iridium-tin mixed oxide anode coatings

Abstract: Mixed oxide coatings of tin and iridium oxide on titanium substrates have been studied over the composition range of 5 to 100 mol % iridium oxide. While stannic oxide behaves as a simple diluent for the electrocatalytically active precious metal oxide, substantial replacement of iridium by tin may be made with little degradation of coating performance in oxygen evolution.

X-ray tube anode with oxide coating

Abstract: The invention relates to enhancing the thermal emissivity of metal X-ray tube anodes by means of applying an oxide coating to the anode. The oxide coating layer is formed of a mixture of zirconium oxide, titanium oxide, aluminum oxide and/or calcium oxide, with silicon oxide added from about 1-20% by weight of said oxide coating layer. Preferably, the coating includes from about 4-7% by weight of silicon oxide. The oxide coating layer is then applied to the anode pursuant to a standard method such as plasma spraying. The oxide coating, as formulated, displays improved layering characteristics over prior formulations while retaining good thermal emissivity and adhesive properties. Moreover, the formulation according to the invention enables an improved application to the anode of such oxides or oxide compounds over previous formulations, without negatively affecting the layer adhesion or thermal emission coefficient properties of the coating. Small quantities of other stabilizing oxide compounds may additionally be added to the oxide coating layer.

Method of analyzing metal impurities in surface oxide film of semiconductor substrate

Abstract: A method of analyzing metal impurities in a surface oxide film of a semiconductor substrate enables a detection sensitivity of the order of 10¹¹ atoms/cm² in a simple technique. This method comprises measuring a quantity of oxide charge resulting from specified metal impurities existing in the surface oxide film formed on the surface of a semiconductor substrate, obtaining a correlation between the quantity of metal impurities and the quantity of oxide charge, and measuring the quantity of metal impurities in the surface oxide film from the quantity of oxide charge of the surface oxide film, based on this correlation. Further, it is possible to obtain the distribution of concentration of the metal impurities in the thermal oxide film on a silicon substrate by obtaining a correlation between a depth of the thermal oxide film and a quantity of oxide charge resulting from the metal impurities in the thermal oxide film and by obtaining a correlation between a quantity of the metal impurities in the thermal oxide film and the quantity of oxide charge resulting

Metallic oxide resistive bodies having a nonlinear volt-ampere characteristic and method of fabrication

Abstract: An electrically resistive body best suited for providing varistors of high surge withstanding capability and high nonlinearity coefficient over a wide range of current magnitudes. The resistive body is composed of a major proportion of metallic oxides including zinc oxide, bismuth trioxide, antimony trioxide, cobaltous oxide, magnesium oxide, manganous oxide, and boric oxide. To these major ingredients there are added minor proportions of boric oxide and aluminum oxide, or of boric oxide and spinel. For the fabrication of such resistive bodies, the mixture of the noted ingredients in finely divided form are molded into desired shape and size, and the moldings are sintered.

Superconducting composite with multilayer patterns and multiple buffer layers

Abstract: An article of manufacture including a substrate, a patterned interlayer of a material selected from the group consisting of magnesium oxide, barium-titanium oxide or barium-zirconium oxide, the patterned interlayer material overcoated with a secondary interlayer material of yttria-stabilized zirconia or magnesium-aluminum oxide, upon the surface of the substrate whereby an intermediate article with an exposed surface of both the overcoated patterned interlayer and the substrate is formed, a coating of a buffer layer selected from the group consisting of cerium oxide, yttrium oxide, curium oxide, dysprosium oxide, erbium oxide, europium oxide, iron oxide, gadolinium oxide, holmium oxide, indium oxide, lanthanum oxide, manganese oxide, lutetium oxide, neodymium oxide, praseodymium oxide, plutonium oxide, samarium oxide, terbium oxide, thallium oxide, thulium oxide, yttrium oxide and ytterbium oxide over the entire exposed surface of the intermediate article, and, a ceramic supercon FIELD OF THE INVENTION The present invention relates to the field of superconducting articles having two distinct regions of superconductive material with differing in-plane orientations whereby the conductivity across the boundary between the two regions can be tailored. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

Morphologies of anodic oxide films deduced from dissolution studies

Abstract: Study of the chemical stripping of anodic oxide films on hafnium, zirconium, tungsten and aluminium has led to the deduction of the morphology of the respective oxides. Away from the boundary region hafnium oxide is a compact, smooth, homogenous and crystalline oxide. Zirconium oxide has a superficial disorder layer which constitutes about 17% of the entire film. Tungsten oxide deposits are composed of two defective partial layers the outer one being more disordered. Aluminium oxide is a porous film. A schematic representation of each film had been presented.

Effects of Iron Content on Electrical Resistivity of Oxide Films on Zr-Base Alloys

Abstract: Measurements of electrical resistivity were made for oxide films formed by anodic oxidation and steam oxidation (400°C/12 h) on Zr plates with different Fe contents. When the Fe content was higher than about 1,000 ppm the electrical resistivity of the steam oxide films was almost equivalent to that of the anodic oxide films, while at lower Fe content the former exhibited lower electrical resistivity than the latter by about 1~3 orders of magnitude. The anodic oxide film was an almost homogeneous single oxide layer. The steam oxide films, on the other hand, were composed of duplex oxide layers. The oxide layer formed in the vicinity of the oxide/metal interface had higher electrical resistivity than the near-surface oxide layer by about 1~4 orders of magnitude. The oxide layer in the vicinity of the interface could act as a protective film against corrosion and its electrical resistivity is one important factor controlling the layer protectiveness. The electrical resistivity of the oxide/metal interfacial ...

Silicon steel sheet having electrolytic-treated insulating film and its production

Abstract: PURPOSE: To inexpensively produce a silicon steel sheet excellent in insulating property and punchability by forming an insulating film consisting of specific amounts of chromium oxide and specific amounts of at least one kind among Al oxide, Zr oxide, etc., on a silicon steel sheet. CONSTITUTION: An electrolytic-treated insulating film consisting of chromium hydrated oxide and/or chromium oxide and at least one kind among Al oxide, Si oxide, Ti oxide, and Zr oxide is formed on the surface of a silicon steel sheet. The amount of chromium hydrated oxide and/or chromium oxide is regulated to 5-50mg/m 2 expressed in terms of chromium, and further, the total amount of at least one kind among Al oxide, Si oxide, Ti oxide, and Zr oxide is regulated, expressed in terms of Al, Si, Ti, and Zr, to a value 0.1-10 times the amount of chromium hydrated oxide and/or chromium oxide expressed in terms of chromium. By this method, the silicon steel sheet having the insulating film excellent in heat resistance, corrosion resistance, and adhesive strength of coating can be produced easily and inexpensively. COPYRIGHT: (C)1992,JPO&Japio

Method and composition of preparing encapsulated ceramic metal oxides

Abstract: Described is a method of preparing an encapsulated ceramic metal oxide and/or silicon oxide precursor comprising the steps: providing a ceramic metal oxide and/or silicon oxide precursor composition; providing a heat resistant resin composition; blending the compositions; encapsulating the ceramic metal oxide and/or silicon oxide precursor by the resin; and recovering the encapsulated ceramic metal oxide and/or silicon oxide. Also described are products of the process and the method of bonding fiber glass substrates by utilizing the encapsulated ceramic metal oxide precursor.

Oxide Ion Conductors for Solid Oxide Fuel Cells

Abstract: This paper reviews the electrical properties of the stabilized zirconia with high mechanical strength and toughness. These oxide ion conductors are attractive for the electrolyte of the self-supported planar type solid oxide fuel cells(SOFC). The electrical conductivity of the tetragonal stabilized zirconia(TZP), which has high bending strength of 1200MPa, was measured to be 6.5x10−2S/cm at 1,000°C. The electrical and mechanical properties of the composites of cubic stabilized zirconia and alumina were examined. The 20 weight% Al2O3 and 80 weight% stabilized zirconia with 8 mole% Y2O3 showed improved mechanical strength and only slight decrease in electrical conductivity.