Showing papers on "Graphene oxide paper published in 1997"

The physical and chemical properties of ultrathin oxide films.

Abstract: Thin oxide films (from one to tens of monolayers) of SiO2, MgO, NiO, Al2O3, FexOy, and TiO2 supported on refractory metal substrates have been prepared by depositing the oxide metal precursor in a background of oxygen (ca 1 x 10(-5) Torr). The thinness of these oxide samples facilitates investigation by an array of surface techniques, many of which are precluded when applied to the corresponding bulk oxide. Layered and mixed binary oxides have been prepared by sequential synthesis of dissimilar oxide layers or co-deposition of two different oxides. Recent work has shown that the underlying oxide substrate can markedly influence the electronic and chemical properties of the overlayer oxide. The structural, electronic, and chemical properties of these ultrathin oxide films have been probed using Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), electron energy loss spectroscopy (ELS), ion-scattering spectroscopy (ISS), high-resolution electron energy loss spectroscopy (HREELS), infrared reflectance absorption spectroscopy (IRAS), temperature-programmed desorption (TPD), scanning tunneling microscopy (STM), and scanning tunneling spectroscopy (STS).

Composite oxide, composite oxide carrier and catalyst

Abstract: The composite oxide and the composite oxide carrier are manufactured by the precursor forming step and firing step. The precursor forming step includes high speed mixing means. The composite oxide catalyst is obtained by preparing a composite of catalytic components simultaneously with the formation of the precursor of composite oxide in the step of forming the precursor of composite oxide. The composite oxide and the composite oxide carrier are composed of a composite oxide in which at least one of cerium and zirconium, and aluminium disperse with extremely high homogeneity. With this structure, the heat resistance of the carrier is improved and consequently, enlargement of particles of the composite oxide defining the carrier, and sintering of adjacent particles of the composite oxide can be restrained, whereby the catalyst using the composite oxide carrier in accordance with the present invention is excellent in heat resistance. With the present invention, the carrier is not limited to a general catalyst carrier. The carrier may be interpreted to indicate general formed bodies. For example, the carrier with the present invention can be also used as materials for sensors and electrodes, optical materials, semiconductors and structure materials. Furthermore, the carrier can be used for a three-way catalyst, NOx catalyst or oxidation catalyst or a part thereof, and a promoter.

Gas sensor and method for manufacturing the same

Abstract: A gas sensor and method for manufacturing a gas sensor is provided. In order to increase the selectivity and the sensitivity to a gas to be measured, a gas-sensitive gallium oxide layer of a gas sensor is coated with a filter layer that comprises silicon dioxide. In an alternative embodiment, the gallium oxide layer can be coated with a gas-sensitive metal oxide layer made of titanium oxide, aluminum vanadate, tungsten oxide or tantalum oxide.

Dielectric breakdown of silicon oxide studied by scanning probe microscopy

Abstract: The applicability of scanning probe microscopy in the dielectric breakdown characteristics of silicon oxide has been demonstrated. Our study demonstrates that the measurement on the oxide is free from the effect of trapped charge created by Fowler–Nordheim tunneling when a sufficient distance is maintained between the measuring points. In this condition, for a 13-nm-thick oxide, the dielectric breakdown voltages were found to be so uniform as to fluctuate only 1%. We applied this method to oxides on the wafers from two different vendors, and found that the dielectric breakdown strength of the oxide depends on the difference on the Si substrates. We also applied this method to a square oxide pattern surrounded by a field oxide, and the result was that the dielectric breakdown strength of the oxide on the edge is lower than the one in the center.

Method to incorporate, and a device having, oxide enhancement dopants using gas immersion laser doping (GILD) for selectively growing an oxide layer

Abstract: A method for forming a uniform and reliable oxide layer on the surface of a semiconductor substrate using projection gas immersion laser doping (P-GILD) is provided. A semiconductor substrate is immersed in an oxide enhancing compound containing atmosphere. The oxide enhancing compound containing atmosphere may include phosphorus, arsenic, boron or an equivalent. A 308 nm excimer laser is then applied to a portion of the substrate to induce incorporation of the oxide enhancing compound into a portion of the substrate. The deposition depth is dependent upon the strength of the laser energy directed at the surface of the substrate. A uniform and reliable oxide layer is then formed on the surface of the substrate by heating the substrate. The laser may be applied with a reflective reticle or mask formed on the substrate. An E 2 PROM memory cell having a program junction region in a silicon substrate is also provided. An oxide layer is positioned between a program junction and a floating gate. The oxide layer is formed by a single or multiple thermal oxidation step(s) to have at least a first oxide thickness due to a GILD oxide enhancing compound underlying a region of the oxide having at least the first oxide thickness.

Conductor paste and multilayer ceramic part using the same

Abstract: High-quality conductor paste which uses an internal conductor containing mainly silver, suppresses the occurrence of voids and cracks resulting from voids even when the paste is baked simultaneously with a ceramic material by a conductor melting method, improves the productivity of multilayer ceramic parts, reduces the cost, and has excellent electric characteristics is prepared by dispersing a conductive material made mainly of silver and a metal oxide in a vehicle. The metal oxide is one or more kinds of metal oxides selected from among Ga oxide, La oxide, Pr oxide, Sm oxide, Eu oxide, Gd oxide, Dy oxide, Er oxide, Tm oxide, and Yb oxide. The baking of the conductor paste is performed at a temperature equal to or higher than the melting point of the conductive material and lower than the boiling point of the material.

Oxide superconductor and method of manufacturing the same

Abstract: An oxide superconductor comprises a base material consisting of a single crystalline oxide, an oxide superconductor film consisting of a Y123 compound and formed on the single crystalline oxide base material, and a coating film consisting essentially of a Ba--Cu--O oxide and covering the surface of the oxide superconductor film, the coating film having a thermal expansion coefficient higher than that of the oxide superconductor film.

Method for making recessed field oxide for radiation hardened microelectronics

Abstract: A method of forming a recessed electrically-insulating field oxide region in a semiconductor substrate is disclosed. In a preferred embodiment, the method includes the steps of oxidizing a surface of the substrate; depositing a polysilicon layer over the oxide layer; depositing a silicon nitride layer over the polysilicon layer; patterning the silicon nitride and polysilicon layers and etching away both layers where the field oxide is to be located; forming a field oxide by thermally oxidizing the substrate in the openings previously formed in the silicon nitride and polysilicon layers; etching away the thermal field oxide; thermally oxidizing the substrate in the etched-away field oxide areas; etching away the silicon nitride layer; optionally, implanting through the thermal oxide with an impurity; depositing a doped oxide; densifying the oxide in a steam ambient; etching back the deposited oxide; then either depositing an undoped CVD oxide, coating the oxide with a leveling layer to planarize the oxide surface, etching both the undoped CVD oxide and leveling layers and etching away the polysilicon; or etching away the polysilicon, leaching the dopants out of the surface of the field oxide structure and passivating the surface in a dry oxygen ambient.

Method for fabricating porous composite oxide

Abstract: A method for fabricating a porous composite oxide is provided. The method includes the steps of: (a) slowly mixing a solution including a silicon oxide source and a solution including an aluminum oxide source; (b) adding hydrochloric acid to the mixed solution prepared in said step (a) to obtain a sol; and (c) adding sodium hydroxide to said sol, reacting the obtained resultant at room temperature for 30 minutes to 12 hours, and drying the resultant. The porous composite oxide has an abundance of fine pores and the distribution of pore size is relatively uniform, so that the porous composite oxide is suitable for a carrier.

Multilayer ceramic part using a conductor paste

Abstract: of EP0853321An object is to provide a conductor paste of quality which uses a silver base internal conductor, suppresses the generation of voids and the concomitant occurrence of cracks even when co-fired with ceramic material by the conductor melting method, and has improved productivity, reduced cost, and improved electrical properties. The conductor paste is prepared by dispersing a silver base conductive material and a metal oxide in a vehicle. At least one of Ga oxide, La oxide, Pr oxide, Sm oxide, Eu oxide, Gd oxide, Dy oxide, Er oxide, Tm oxide, and Yb oxide is used as the metal oxide. The conductor paste is fired at a temperature between the melting point and lower than the boiling point of the conductive material.