An object of the present invention is to provide a high-density Cr—Si—C-based sintered body including chromium (Cr), silicon (Si) and carbon (C) and is furthermore to provide at least one of the high-density Cr—Si—C-based sintered body, a sputtering target including the sintered body or a method for producing a film using the sputtering target. The present invention can provide a Cr—Si—C-based sintered body including chromium (Cr), silicon (Si) and carbon (C), wherein the sintered body has a relative density of 90% or more and a porosity of 13% or less.

It is difficult for a Cr—Si-based sintered body composed of chromium silicide (CrSi.sub.2) and silicon (Si) to have high strength.

Provided is a Cr—Si-based sintered body including Cr (chromium) and silicon (Si), in which the crystal structure attributed by X-ray diffraction is composed of chromium silicide (CrSi.sub.2) and silicon (Si), a CrSi.sub.2 phase is present at 60 wt % or more in a bulk, a density of the sintered body is 95% or more, and an average grain size of the CrSi.sub.2 phase is 60 μm or less.

New copper-coated titanium diboride electrodes are disclosed. The copper-coated titanium diboride electrodes may be used in an aluminum electrolysis cell. In one embodiment, a method includes installing the copper-coated titanium diboride electrode in the aluminum electrolysis cell and operating the aluminum electrolysis cell. During start-up, the aluminum electrolysis cell may be preheated and a bath may be formed from a molten electrolyte. Alumina (Al.sub.2O.sub.3) may in the added to the bath and reduced to aluminum metal. At least some of the copper film of the copper-coated titanium diboride electrode may be replaced by an aluminum film, thereby forming an aluminum-wetted titanium diboride electrode.

A composition includes a plurality of microparticles, where the microparticles comprise agglomerates of nanopowder, wherein the nanopowder includes a material selected from the following: a ceramic material, a metal, an alloy, a polymer, or a combination thereof. The microparticles are characterized by having an essentially spherical shape, nanograin features substantially identical to nanograin features of the nanopowder prior to formation into the microparticles, and a nanoscale porosity defined by the nanograin features. The plurality of microparticles have an essentially uniform size relative to one another. Moreover, the composition has flowability having a Hausner Ratio representing tapped density:bulk density less than 1.25.

The present invention provides a gallium nitride sintered body and a gallium nitride molded article which have high density and low oxygen content without using a special apparatus. According to the first embodiment, a gallium nitride sintered body, which is characterized by having density of 2.5 g/cm.sup.3 to less than 5.0 g/cm.sup.3 and an intensity ratio of the gallium oxide peak of the (002) plane to the gallium nitride peak of the (002) plane of less than 3%, which is determined by X-ray diffraction analysis, can be obtained. According to the second embodiment, a metal gallium-impregnated gallium nitride molded article, which is characterized by comprising a gallium nitride phase and a metal gallium phase that exist as separate phases and having a molar ratio, Ga/(Ga+N), of 55% to 80%, can be obtained.

Disclosed here is a method for producing a graphene macro-assembly (GMA)-fullerene composite, comprising providing a mixture of graphene oxide and water, adding a hydroxylated fullerene to the mixture, and forming a gel of the hydroxylated fullerene and the mixture. Also described are a GMA-fullerene composite produced, an electrode comprising the GMA-fullerene composite, and a supercapacitor comprising the electrode.

The present invention provides a silicon nitride sintered substrate capable of reducing contamination caused by a boron nitride powder or the like used as a releasing agent and problems in bonding strength and dielectric strength at the time of laminating metal layers or the like, where the contamination is caused by a network structure provided by a silicon nitride crystal formed on the surface of the substrate in an unpolished state after sintering a silicon nitride powder. The silicon nitride substrate in an unpolished state after sintering is a silicon nitride sintered substrate where a cumulative volume of pores having a diameter in a range of 1 to 10 μm is not more than 7.0'10.sup.−5 mL/cm.sup.2 in a measurement by a mercury porosimetry. Preferably, Ra of the surface is not more than 0.6 μm and arithmetic mean peak curvature (Spc) of a peak is not more than 4.5 [l/mm].

Provided is a method for continuously producing a silicon nitride sintered compact for enabling a continuous production of silicon nitride sintered compacts by sintering using a silicon nitride powder having a high β-phase rate. A fired compact 1 housed in a firing jig 2 contains a silicon nitride powder having at least 80% of β-transition rate and 7 to 20 m.sup.2/g of specific surface area together with a sintering additive, where the total content of aluminum element is adjusted not to exceed 800 ppm. The firing jig 2 is supplied into a continuous firing furnace equipped with a closed-type firing container 5 having at its end portions a supplying openable door 3 and a discharging openable door 4 for supplying and discharging the firing jig, a heating mechanism 6 provided on the body periphery of the firing container 5, a conveyance mechanism for supplying/discharging the firing jig into/from the firing container, and a gas-supplying mechanism for supplying an inert gas into the firing container, so that the silicon nitride is heated to a temperature in the range of 1200 to 1800° C. in an inert gas atmosphere and at a pressure of not less than 0 MPa.Math.G and less than 0.1 MPa.Math.G so as to be sintered.

In the present invention, in producing a SiC single crystal in accordance with a solution method, a crucible containing SiC as a main component and having an oxygen content of 100 ppm or less is used as the crucible to be used as a container for a Si—C solution. In another embodiment, a sintered body containing SiC as a main component and having an oxygen content of 100 ppm or less is placed in the crucible to be used as a container for a Si—C solution. The SiC crucible and SiC sintered body are obtained by molding and baking a SiC raw-material powder having an oxygen content of 2000 ppm or less. SiC, which is the main component of these, serves as a source for Si and C and allows Si and C to elute into the Si—C solution by heating.

In a diamond polycrystal, a value of a ratio (a′/a) of a′ to a is less than or equal to 0.99 in a Knoop hardness test performed under a condition defined in JIS Z 2251:2009, where the a represents a length of a longer diagonal line of a first Knoop indentation formed in a surface of the diamond polycrystal when a Knoop indenter with a test load of 4.9 N is pressed onto the surface of the diamond polycrystal, and the a′ represents a length of a longer diagonal line of a second Knoop indentation remaining in the surface of the diamond polycrystal after releasing the test load.