Abstract: To produce a high-temperature superconductor of the composition Bi.sub.2 (Sr,Ca).sub.3 Cu.sub.2 O.sub.8+x having a strontium to calcium ratio of 5:1 to 2:1 and a value of x between 0 and 2, the oxides and/or carbonates of bismuth, strontium, calcium and copper are vigorously mixed in a stoichiometric ratio. The mixture is heated at a temperature of 870.degree. to 1100.degree. C. until a homogeneous melt is obtained. The melt is poured into mold and allowed to solidify in them. The cast bodies removed from the molds are annealed for 6 to 30 hours at 780.degree. to 850.degree. C. Finally, the annealed cast bodies are treated for at least 6 hours at temperatures of 600.degree. to 820.degree. C. in an oxygen atmosphere. The cast bodies can be converted into shaped bodies of the desired sizes by mechanical processes before they are annealed. The shape and size of the shaped bodies may also be determined by the shape and dimensioning of the mold used in producing the cast bodies.

Abstract: A composition and method of preparing YBa.sub.2 Cu.sub.3 O.sub.7-x superconductor. Addition of tin oxide containing compounds to YBCO superconductors results in substantial improvement of fracture toughness and other mechanical properties without affect on T.sub.c. About 5-20% additions give rise to substantially improved mechanical properties.

Abstract: A new superconducting material composed mainly of compound oxide represented by the general formula:Tl.sub.h Ca.sub.j .alpha..sub.k(1-y) .beta..sub.ky Cu.sub.m O.sub.nwherein".alpha." represents Ba or Sr;".beta." represents any one of elements selected from a group comprising Na, K, Rb and Cs;"h", "j", "k", "m" and "n" are the atomic ratios each satisfies the following range:1.ltoreq.h.ltoreq.3, 1.ltoreq.j.ltoreq.3, 1.ltoreq.k.ltoreq.3,2.ltoreq.m.ltoreq.4 and 5.ltoreq.n.ltoreq.15 and"y" is a number which satisfies a range of 0.05.ltoreq.y.ltoreq.0.8.

Abstract: A method of using dicalcium silicate, and particularly dicalcium silicate slag, to produce wollastonite. In a particular embodiment, the method is used for the production of ceramic products, such as wall tile, containing wollastonite. The method includes preparing a batch mix comprising dicalcium silicate slag and a silica source, and preferably a fluxing agent, then firing the batch mix to produce wollastonite. The method can further include adding a binder material and water to the batch mix, and then pressing the resulting batch mix to form a desired shape, prior to firing. Also, a composition, such as a ceramic product, than is produced from a dicalcium silicate slag mixed with a silica source and fired such than the dicalcium silicate in the slag and the silica source undergo a phase change to become wollastonite.

Abstract: A description is given of a solid oxide-ceramic superconductor containing copper in the crystal lattice which is composed of crystals which are arranged essentially in parallel and intergrown with one another and which also contains, per 100 g of copper in the superconductor, 0.04 to 0.5 mol of CuF.sub.2 or KF, and of a sinter process for producing it. The copper-containing superconductor may be made up, for example, of bismuth, strontium, calcium or of bismuth, strontium, calcium, lead and also copper and oxygen.

Abstract: Unexpected results were obtained when Tl-1223 and Tl=-2223 superconductive materials were annealed at respectively pre-determined annealing temperatures. The optimum annealing temperatures for Tl-1223 and Tl-2223 superconductive materials are found to be 860.degree. C. and 820.degree. C., respectively. By incorporating the optimum annealing temperature and an optimum annealing envirenment, which is expressed in terms of oxygen partial pressure, into the manufacturing process, the present invention presents a method which can substantially increase the critical temperature of thallium based superconductive materials with greatly reduced annealing time and with improved reproducibility, and is thus superior to any method disclosed in the prior art.

Abstract: Process for preparing a high temperature superconductor such as yttrium bum copper oxides, by dissolving suitable proportions of hydrolyzable salts, oxides, or organometallic compounds of yttrium, barium and copper in an acid pH-controlled water-containing organic solvent such as methanol, and subjecting the resulting solution to ultrasonic energy or to an oxidation-reduction reaction, preferably while passing oxygen under a positive pressure through the solution, and precipitating a hydrolyzed precursor material. Such precursor material is then heated or annealed at temperatures between about 300.degree. C. and about 600.degree. C., also preferably in the presence of flowing oxygen, to produce the desired high temperature superconductor material.

Abstract: A process for obtaining a synthetic refractory sand for use in steelmaking, said synthetic refractory sand being free-flowing, comprising at least 50% forsterite, having semi-angular and irregularly shaped grains, lenses and flat grains, a specific gravity of approximately 3 g/cm.sup.3, a void volume of less than approximately 50%, a coefficient of thermal expansion of approximately 1.09.times.10.sup.-5 and a fusion point of at least 1610.degree. C. including the steps of: (a) agglomerating a mixture comprising a particulate starting material selected from the group consisting of serpentine-containing asbestos tailings and an enstatite-containing product produced by calcining serpentine-containing asbestos tailings and from 10% to 25%, based on the total weight of mixture, of magnesium oxides or precursors of magnesium oxides with an aqueous binder solution to obtain agglomerates of said mixture; (b) calcining said agglomerates at a temperature of from 1200.degree. C. to 1500.degree. C.

Abstract: A castable refractory composition for use in the production of cast refractory piece, which comprises 1 part by weight of a phosphoric acid solution (H.sub.3 PO.sub.4) having a concentration ranging from 40 to 85% and its primary acidic function partially neutralized by reaction with vermiculite; from 0.1 to 2.5 parts by weight of a mineral such as wollastonite that is refractory and of fibrous structure and may react with one part of the acidic functions of the phosphoric acid that are still free or not neutralized yet; from 0.1 to 2.5 parts by weight of another mineral such as serpentine, MgO or synthetic olivine, containing at least one cation that may react with another part of the acidic functions of the phosphoric acid that are still free or not saturated yet; and from 0.28 to 1.45 parts by weight of water, being provided that the more concentrated is the phosphoric acid solution, the higher is the amount of water to be present in the composition.

Abstract: A single phase superconducting oxide ceramic material in the form of highly oriented platelets, and a process for the production thereof. The process involves calcining in a non-reducing atmosphere a homogeneous mixture of stoichiometric proportions of suitable precursor materials. The calcination temperature is below the peritectic melt temperature of the superconducting material, and is at or above a temperature and for a time sufficient to effect partial melting of at least one of the precursor materials to a degree sufficient to effect diffusion of at least one of the precursor materials throughout the mixture. The calcination vessel is not wetted by melts of the precursor materials at the calcination temperature. The calcined material is then annealed in a non-reducing atmosphere. A typical material produced by the process is YBa.sub.2 Cu.sub.3 O.sub.x superconducting material, at a calcination temperature of about 976.degree.-982.degree. C.

Abstract: Described in a joining agent for joining electrically ceramic bodies by heating the joining agent inserted at the parts to be jointed between the ceramic bodies with an electric current flowing predominantly through the joining agent at high temperature. The joining agent is superior in the wetability and reactivity with the ceramics to ensure the joint part strength. The joining agent includes, as an electric conductor, an electric conductive component made of an ion conductor consisting of fluoride, chloride, and/or oxide, which forms carrier ions by the pre-heating and has an electric conductivity higher than that of the ceramic body at the electric current supplying time. During the supplying electric current to time, the joining agent has the electric resistance increased gradually at the molten state of the joining agent by decreasing the density or the mobility of the carrier ions.

Abstract: Alkaline earth metal indates of the formula (Sr,Ca)In.sub.2 O.sub.4 can be converted by sintering or fusing into compact moldings which, owing to their stability are suitable even at temperatures of at least 800.degree. C. as reaction vessels for chemical reactions in the presence of bismuth (III) oxide and/or alkaline earth metal oxides.

Abstract: The materials for living hard tissue replacements of the present invention comprise a ceramic material which contain Cao and SiO.sub.2 as essential components, and MgO as an optional components, are substantially free from calcium phosphate and are capable of forming a compound based on calcium phosphate by contact with an aqueous solution containing phosphorus, and show high biological affinity.

Abstract: An invention is shown in which a quicklime is hydrated in the presence of a special chemical modifier to produce a controlled temperature hydrate having improved plastic properties and greater surface areas.

Abstract: A vestibule block or interior furnace wall utilized in a diffusion furnace for manufacturing semi-conductors, integrated circuits and the like, and which is made of refractory or ceramic material, is treated on its surface with a suspension of fine particulate of a glass frit composition comprising an alkali earth metal alumino silicate, and is thereafter heated above the transition temperature of the alkali earth metal alumino silicate. Vestibule blocks and interior surface walls which have been treated in the above-described manner are highly abrasion resistant on their surface, generate virtually no particulate matter under conditions of ordinary use in the semi-conductor manufacturing processes, and generate significantly less particulate matter when tested in an abrasion test against vestibule blocks of the prior art.

Abstract: Compounds that satisfy the general formula A.sub.1-Y.sup.4+ A.sub.Y.sup.1+ A.sub.Y.sup.3+ V.sub.2-X P.sub.X O.sub.7 exhibit isotropic NTE behavior in the range of normal ambient temperatures. Y is from about 0.0 to about 0.4, and more preferably is about 0.2. X is from about 0.6 to about 1.4, and is more preferably about 1. Particularly suitable NTE compounds have X about 1 and Y about 0. A.sup.4+ is selected from the group consisting of Hf, Zr, Zr.sub.a M.sub.b, Hf.sub.a M.sub.b and mixtures thereof wherein a plus b equals one and M is selected from the group consisting of Ti, Ce, Th, U, Mo, Pt, Pb, Sn, Ge and Si. More preferably, A.sup.4+ is selected from the group consisting of Hf and Zr. A.sup.1+ is selected from the group consisting of the alkali earth metals, and A.sup.3+ is selected from the group consisting of the rare earth metals. Such NTE materials exhibit isotropic negative linear expansion at a temperature below about 100.degree. C.

Abstract: A high-Tc oxide superconductor including Bi, Sr, Ca, Cu, O and at least one of Pb and Al, with a high critical temperature than that of liquid nitrogen. A method for producing the high-Tx oxide superconductor is also disclosed, in which Bi.sub.2 O.sub.3, SrCO.sub.3, CaCO.sub.3, CuO and PbO or Al.sub.2 O.sub.3 powders are mixed, calcined, ground, cold-pressed and sintered. The calcined mixture may be melted and annealed to obtain a tape-form superconductor.

Abstract: A barrier layer for prevention of solid fluorides penetration, e.g. NaF, from the interior of an aluminum production cell holding a fluoride-containing melt into a refractory layer intended to provide heat and electrical insulation for the cell. The barrier layer contains CaO, which may be derived from a CaO precursor such as calcite (CaCO.sub.2) by decomposition during cell start-up. Since CaO does not appear to react with sodium fluoride (NaF), and indeed according to thermodynamic calculations seems incapable of doing so at cell operating temperatures, it is effective for preventing the penetration of that compound when the latter is in the solid state. The barrier layer makes it possible to use insulating low cost refractories which are attacked by solid fluorides in the cell wall lining with improvement of the life of such materials.

Abstract: The present invention relates to a method to manufacture a composite ceramic material having a high strength combined with bioactive properties, when the material is used as a dental or orthopedic implant, which includes preparing a powder mixture, mainly comprising partly a first powder, which in its used chemical state will constitute a bioinert matrix in the finished material , and partly a second powder, mainly comprising a calcium phosphate-based material. The invention is characterized in that said first powder comprises at least one of the oxides belonging to the group consisting of titanium dioxide (TiO.sub.2), zirconium oxide (ZrO.sub.2) and aluminum oxide (Al.sub.2 O.sub.

Abstract: Improved processes for making thin film and bulk thallium superconductors are described, as well as Tl superconductors having high critical current densities and low surface impedance. An annealing step in a reduced oxygen atmosphere is used to convert compounds containing thallium, calcium, barium and copper to a Tl-2223 superconducting phase or to convert an oxide having the nominal composition Tl.sub.2 Ca.sub.2 Ba.sub.2 Cu.sub.3 O.sub.x to a crystalline Tl-2223 phase. The oxygen pressure during annealing is controlled to be below the thermodynamic stability limit for conversion of Tl-2223 to Tl-2122 and secondary phases. Temperatures less than 880.degree. C. are used, the oxygen pressure being sufficient to prevent excess thallium loss so that the Tl content in the final Tl-2223 phase is Tl.sub.1.6-2.0. Electrical devices including SQUIDs can be made with these improved superconductors.

Abstract: A method of growing mixed crystals having at least two lattice sites each having a different number of adjacent oxygen ions from melts of oxidic multi-component systems, homogeneous mixed crystals being grown such that the cations intended to occupy the first lattice site having the highest number of adjacent oxygen ions and to occupy the second lattice site having the next lowest number of adjacent oxygen ions are chosen such that the ratio of the bond length of the cations in the first lattice site to the bond length of the cations in the second lattice site is in the range from 0.7 to 1.5.

Abstract: This invention provides an oxide superconductor having a composition of the following general formula of (Tl.sub.a Bi.sub.b Pb.sub.c).sub.x (Sr.sub.d Ba.sub.e).sub.2y (Ca.sub.f Ln.sub.g).sub.y(n-1) Cu.sub.wn O.sub.2n+3+.delta., wherein Ln is at least one selected from Y and rare earth elements, n is 2, 3 or 4, -1<.delta.1, 0.8.ltoreq.x.ltoreq.1.2, 0.8.ltoreq.y.ltoreq.1.2, 0.8.ltoreq.z.ltoreq.1.2 and 0.8.ltoreq.w.ltoreq.1.2, and if a, b and c all are not zero, i.e., greater than zero, a+b+c=1, d+e=1 and f+g=1, and 0<a.ltoreq.1, 0<b.ltoreq.1, 0<c.ltoreq.1, 0.ltoreq.d.ltoreq.1, 0.ltoreq.e.ltoreq.1, 0.3.ltoreq.f.ltoreq.0.99 and 0.01.ltoreq.g.ltoreq.0.7; if b is zero, a+b+c=1, d+e=1 and f+g=1, and 0<a.ltoreq.1, 0<c.ltoreq.1, 0<d<1, 0<e<1, 0.3.ltoreq.f.ltoreq.0.99 and 0.01.ltoreq.g.ltoreq.0.7; if c is zero, a+b+c=1, d+e=1 and f+g=1, and 0<a.ltoreq.1, 0<b.ltoreq.1, 0.ltoreq.d.ltoreq.1, 0.ltoreq.e.ltoreq.1, 0.3.ltoreq.f.ltoreq.0.99 and 0.01.ltoreq.g.ltoreq.0.

Abstract: A self-fluxing binder composition for use in the pelletization of an ore concentrate, especially iron ore concentrates. The composition comprises from 50 to 98% by weight of one or more carrier having a high surface area, and from 2 to 50% by weight of a water soluble organic enhancer. The carrier is selected from the group consisting of natural and synthetic magnesium and/or calcium bearing minerals and preferably consists of synthetic, fibrous-like forsterite. The enhancer is selected amongst the natural polysaccharides, of high viscosity, and more preferably amongst the natural gums of high viscosity such as the guar or xanthan gum and amongst starch and is derivatives. The use of such a self-fluxing binder composition improves the properties of the green and dry pellets and makes them more easy to handle, as compared to those produced with other conventional binders. Moreover, the pellets that are produced with such a binder composition have improved metallurgical properties.

Abstract: A nonmagnetic oxide substrate material has a composition of 15 to 60 mol % of NiO, 10 to 70 mol % of CoO, 10 to 40 mol % of TiO.sub.2, and 0.5 to 25 mol % of CaO and is formed of very minute crystal grains. Preferably MgO or ZrO.sub.2 is used as an additive to the material to present a total composition containing the additive of 0.5 to 3 wt % per 100 parts by weight of the nonmagnetic oxide substrate material. Preferably, the substrate material is formulated to have a thermal expansion coefficient falling in the range of from 100 to 140 X 10.sup.-7 /.degree.C. A magnetic head using this substrate material reduces the loss in surface smoothness due to the relative slide with the magnetic tape.

Abstract: Disclosed are an oxide superconductor, and an optimum process for producing the same. The oxide superconductor comprises a base material phase including an oxide superconducting material, the oxide superconducting material including barium (Ba) at least and being free from grain boundaries, and precipitation phases contained in an amount of 1 to 50% by volume in the base material phase and dotted therein in a manner like islands, the precipitation phases being oxides of a metal selected from the group consisting of silicon (Si), aluminum (Al), zirconium (Zr), magnesium (Mg), titanium (Ti), strontium (Sr), tungsten (W), cobalt (Co) and vanadium (V), and being products of decomposition reaction of the base material phase. In the production process, the constituent materials are treated thermally at a partially melting temperature in order to give the above-described novel structure to the oxide superconductor.

Abstract: The present invention is characterized in that oxides of Y, Ba and Cu having a superconductive substance-forming composition are melted, the melt is rapidly cooled and solidified, the obtained sheet is heated at a temperature of 1000.degree. to 1350.degree. C. to produce a partially melted state thereof, and the sheet is gradually cooled at a rate lower than 200.degree. C./hr, whereby a texture in which grains of the RE.sub.2 BaCuO.sub.5 phase having a diameter smaller than 20 .mu.m are dispersed in the REBa.sub.2 Cu.sub.3 O.sub.7-y phase is obtained.

Abstract: A method of manufacturing a component of the tape or filament kind out of a material based on a superconducting oxide having a high critical temperature, wherein said material is formed while it is in the vitreous state,the method being characterized by the fact that the material is subsequently crystallized:in a first step under a magnetic field and at a temperature T.sub.l lying between the vitreous transition temperature T.sub.g and the crystallization temperature T.sub.x, during which step isolated microcrystallites of submicroscopic size develop and their c axes orient themselves parallel to one another because of said applied magnetic field; andin a second step at a temperature T.sub.2 close to the crystallization temperature, in which the existing nuclei grow while retaining the texture imparted to them during said first step.

Abstract: Mixed oxygen ion and electronic conducting bismuth oxide based ceramic materials having high ambipolar activity which can be fabricated into thin membranes for high efficiency oxygen separation from air at intermediate temperatures. The ceramic materials may be homogeneous microstructures in the form of solid solutions or compounds or may be composite non-homogeneous microstructures of a separate substantially continuous oxygen ion conductive phase and a substantially continuous electronic conductive phase.

Abstract: Textured, dense, polycrystalline ceramic bodies are produced by a sinter-compression process which exhibit anisotropic superconducting properties. The bodies are produced from low density aggregates of crystalline particles by applying compressive forces to two opposed faces while permitting the aggregate to expand perpendicularly to the axis of compression. This produces a microcrystalline structure predominately composed of elongated platelike grains having their broad faces generally aligned with the body faces to which the compression was applied. The resulting bodies exhibit room temperature conductivity several times greater in a direction parallel to their compression faces than perpendicular thereto.

Abstract: A process for producing beryllium oxide (BeO) from beryllium hydroxide (Be(OH).sub.2) in a single reactive step. Beryllium hydroxide powder is mixed with a calcination additive containing Mg and/or Ca and calcined at 1000.degree.-1300.degree. C. The resultant oxide pow-der is characterized by low fluorine content (<100 ppm), low surface area (<1.5 m.sup.2 /g) and a controlled particle size of 2 .mu.m to 25 .mu.m.

Abstract: A refractory adhesive and filler paste composition is described which can be extruded, trowelled or parged onto a refractory surface. The composition can be used to adhesively secure shaped refractory articles together or used as a filler. The composition contains refractory grain particles having critical size limitations and a non-aqueous binder system which includes an unsaturated drying oil such as tung or linseed oil and an organic solvent such as naphtha. The composition may be premixed and packaged in a caulking gun cartridge and applied by extrusion.

Abstract: Guanidine oxalate is used as a precipitating agent in the coprecipitation of multicomponent oxide powder precursors. A solution of a soluble inorganic salt is combined with a solution of guanidine oxalate. A resultant metal oxalate is precipitated from the solution and can thereafter be subjected to heat to convert the metal oxalate into a multicomponent ceramic powder.

Abstract: Ceramic binder for forming and processing ceramic ware, comprising a sol-gel of a mixture of highly charged metal hydroxy cations and one or more low charged metal hydroxy cations, which are able to form an aqueous sol.

Abstract: A composition comprising an alpha alumina substrate having a first coating layer of calcium pyrophosphate and a second coating layer of hydrous alumina, and to a calcined composition comprising an alpha alumina substrate having a first coating layer of calcium pyrophosphate and a second coating layer of a densified anhydrous, crystalline form of alumina and to a method for preparing the same.

Abstract: A process of preparing a yttrium based superconductor including partial melting a body of YBa.sub.2 Cu.sub.3 O.sub.y compound which is stacked on a Y.sub.2 BaCuO.sub.5 plate, to produce a liquid phase, BaCu.sub.2.CuO which flows down into the Y.sub.2 BaCuO.sub.5 plate, a peritectic reaction of the Y.sub.2 BaCuO.sub.5 of the plate, with the liquid phase, BaCuO.sub.2.CuO, to form a YBa.sub.2 Cu.sub.3 O.sub.y phase, and cooling and annealing the resulting YBa.sub.2 Cu.sub.3 O.sub.y to gain superconducting properties, in which weak-links are reduced by the well oriented-grains with few voids, and the grains of the fine grained Y.sub.2 BaCuO.sub.5 phase act as flux pinning centers, which increases the critical current density.

Abstract: High-frequency dielectric ceramics which contains the oxide of a complex perovskite structure as the main component, have a mean crystal gain size of sintered ceramic controlled to within the range of 5 .mu.m to 20 .mu.m and a porosity not exceeding 7% and provides high unloaded Q without requiring long-hour sintering or heat treatment.

Abstract: Complex superconducting oxides are fabricated through appropriate selection and use of fundamental superconducting "building blocks." In this fashion, the invention provides a rationalized method of fabricating complex oxides having desirably high T.sub.c values. In another aspect of the invention, novel, 112 and 12 superconducting oxides are described.

Abstract: Self-supporting bodies are produced by reactive infiltration of a parent metal into a boron donor material and a carbon donor material. The reactive infiltration typically results in a composite comprising a boron-containing compound, a carbon-containing compound and residual metal, if desired. The mass to be infiltrated may contain one or more inert fillers admixed with the boron donor material and carbon donor material. The relative amounts of reactants and process conditions may be altered or controlled to yield a body containing a wide ranging varying volume percentage of ceramic, metal, and porosity.

Abstract: 1. In the (Bi,Tl)-Ca-(Sr,Ba)-Cu-O based superconducting ceramics production process, a process for preparing superconducting ceramics characterized by(a) providing powders includingi) a compound of Bi oxide or Tl oxide,ii) a Ca compound,iii) an Sr compound or Ba compound, andiv) a Cu compoundas starting powders;(b) compounding and mixing powders from compounds of the starting powders, the compounds each having lower vapor pressure, i.e., powders from compound ii), compound iii), and compound iv) at a compounding ratio to obtain a mixture, and primarily calcining the mixture at a temperature of 850.degree. to 1050.degree. C., to form a Ca--(Sr,Ba)--Cu--O based oxide; and(c) further mixing the Ca--(Sr,Ba)--Cu--O based oxide with a compound having a higher vapor pressure, that is, the powder of compound i), at a compounding ratio, and secondarily calcining at a temperature of 500.degree. to 820.degree. C.

Abstract: A Bi-Pb-Sr-Ca-Cu-O system superconductor having a composition ofBi.sub.n Pb.sub.m Sr.sub.x Ca.sub.y Cu.sub.2 O.sub..delta.wherein n is a number from 0.76 to 1.05, m is a number from 0.01 to 0.20, x is a number from 0.85 to 1.35 and y is a number larger than 1.00 and not larger than 1.35; or n is a number larger than 1.06 and not larger than 1.15, m is a number from 0.12 to 0.25, x is a number from 1.20 to 1.35 and y is a number from 1.20 to 1.30; or n is a number larger than 0.75 and not larger than 1.15, m is a number from 0.25 to 0.35, x is a number from 1.20 to 1.35 and y is a number from 1.20 to 1.35, when they are normalized with the Cu mole number of 2, which has t.sub.c of at least 110 K.

Abstract: An oxide type superconducting material comprising a plurality of metal species and oxygen in combined form, said superconducting material improved by the addition of a parametric modifier.

Abstract: Novel superconducting oxide compositions of the formulas (YBa.sub.2 Cu.sub.3.25).sub.a O.sub.z and Y.sub.2 Ba.sub.4 Cu.sub.8 O.sub.20-x (248) are provided which can have an ordered defect structure stacked on one axis. MiThis invention was made with Government support under contracts DMR-8616055 awarded by the National Science Foundation and F49620-88C-0004 awarded by the United States Air Force. The Government has certain rights in this invention.

Abstract: Superconductors having a composition Bi.sub.2-a-b-c Sn.sub.a Pb.sub.b Sb.sub.c Sr.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+4 can be made by firing the appropriate mixtures of designated oxides or carbonates. In the composition a=about 0.001-0.4, b about 0-0.4, c about 0-0.4, and n 2 or 3. The addition of Sn improves the superconductive properties of comparable compositions that lack Sn. For example, Bi.sub.1.6 Sn.sub.0.4 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.x (x=ca 10), calcined at 830.degree. C. for 15 hours shows superconductivity by magnetic susceptibility tests at about 77.degree. K. whereas Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10 prepared under the same conditions but lacking Sn, shows nothing at this temperature.

Abstract: The present invention provides an oxide superconductor which has a relatively high transition temperature T.sub.c. This superconductor has the chemical formula (R.sub.1-x Ca.sub.x)(Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.3 O.sub.7-z wherein R is at least one rare earth element selected from the group consisting of Tm, Yb and Lu, x is with in the range of 0.1.ltoreq..times.0.5, y is within the range of 0.1.ltoreq. y .ltoreq.0.4 and z is within the range of 0.05 .ltoreq. z .ltoreq.(x/2+0.5). The invention further provides a method for producing the oxide superconductor which comprises firing a composition of the formula (R.sub.1-x Ca.sub.x)(Ba.sub.1-y Sr.sub.y).sub.2 Cu.sub.3 O.sub.7-z wherein R is at least one rare earth element selected from the group consisting of Tm, Yb and Lu, x is within the range of 0.1 .ltoreq..times..ltoreq.0.5 and y is within the range of 0.1 .ltoreq.y .ltoreq.0.4 at a temperature of from 750.degree. C. to the melting temperature of the composition under an oxygen partial pressure P(O.sub.

Abstract: A high temperature superconductor system having the nominal composition: Tl-Ba-Ce-Cu-O. The high temperature superconductor of the present invention has a transition temperature of about 90 K. Processes for making the high temperature superconductor are also provided.

Abstract: A machinable high Tc ceramic superconductor is formed by weighing and mixing appropriate stoichiometric amounts of Bi.sub.2 O.sub.3, SrCO.sub.3, CaCO.sub.3, and CuO (BSCCO), removing carbonates from the mixture, melting the mixture, casting the melted mixture into a mold, and inducing superconductivity and growth of randomly oriented platelets in the cast.

Abstract: Calcium phosphate series compound ceramics are provided in which heat-resistant inorganic short fibers such as flawless SiC or Si.sub.3 N.sub.4 are three-dimensionally dispersed in a matrix composed of calcium phosphate series compound and entangled with each other to form a high strength shaped body as well as a method of producing the same. Also, a high density silicon carbide ceramic is provided in which biological glass is impregnated and filled in a porous shaped body. These composite ceramics have high strength and high toughness and are suitable as a heat-resistant structural material or a material for bio hard texture.

Abstract: An oxide-based strengthening and toughening agent, such as tetragonal Zro.sub.2 particles, has been added to copper oxide superconductors, such as superconducting YBa.sub.2 Cu.sub.3 O.sub.x (123) to improve its fracture toughness (K.sub.IC). A sol-gel coating which is non-reactive with the superconductor, such as Y.sub.2 BaCuO.sub.5 (211) on the ZrO.sub.2 particles minimized the deleterious reactions between the superconductor and the toughening agent dispersed therethrough. Addition of 20 mole percent ZrO.sub.2 coated with 211 yielded a 123 composite with a K.sub.IC of 4.5 MPa(m).sup.0.5.

Abstract: A fine stoichiometric superconductor powder may be co-precipitated from the addition of appropriate metal compound powders in ammonium carbonate. The co-precipitated powder is very homogeneous because the reaction progresses in liquid solution. For example, YBa.sub.2 Cu.sub.3 O.sub.7-x superconducting powder may be prepared by the co-precipitation of yttrium oxide, copper (I) acetate, copper (II) acetate and barium acetate. The acetates precipitate by nucleating on the yttrium oxide particles. The process permits a relatively wide window of starting reactant proportions yet still produce ceramics having superconductive properties.

Abstract: The invention relates to a process for lining a distributor for continuous casting of metals, in particular steel, according to which the layer of refractory wear lining is placed in position in aqueous form, characterized in that the said refractory wear lining is composed of raw natural dolomite or raw natural calcite or of a mixture of these two materials, in that its particle size is between 0 and 5 mm, in that a binder, in proportions of 0.5 to 5% by weight, and an inorganic or organic plasticiser, in proportions of 0.2 to 3% by weight, are incorporated in this lining and in that the decarbonization of this lining is carried out after it has been placed in position, during the drying and the calcining thereof.The invention also relates to a distributor lined in this way and to the refractory lining itself.