A MgF.sub.2—CaF.sub.2 binary system sintered body for a radiation moderator having a compact polycrystalline structure excellent in radiation moderation performance, especially neutron moderation performance, comprises MgF.sub.2 containing CaF.sub.2 from 0.2% by weight to 90% by weight inclusive, having a bulk density of 2.96 g/cm.sup.3 or more, and a bending strength of 15 MPa or more and a Vickers hardness of 90 or more as regards mechanical strengths.

A technique of forming a carbon-carbon composite that includes infiltrating a preform comprising carbon fibers or carbon-precursor fibers with a pitch and pyrolyzing the pitch using a controlled pressure and temperature ramp rate to control a growth of optical textures as the pitch is pyrolyzed to a coke matrix. Pyrolyzing the pitch may include initiating pyrolysis of at least some of the pitch at a first pressure less than about 2000 psi and a first temperature ramp rate between about 5 ° C./hr and about 50 ° C./hr to a first target temperature, and pyrolyzing at least some of the pitch at a second pressure greater than 2000 psi and a second temperature ramp rate between about 5 ° C./hr and about 50 ° C./hr to a second target temperature, where the second target temperature is greater than the first target temperature.

Provided is a ceramic member in which the difference in thermal expansion coefficient between an insulating ceramic material and an electrically conductive ceramic material is extremely small and therefore any mismatch caused in association with this difference in thermal expansion coefficient does not occur, and which does not undergo any failure such as breakage, cracking, detachment or destruction. The ceramic member (1) includes an electrically conductive ceramic material (2) which contains yttrium oxide as the main component and additionally contains a fibrous electrically conductive substance such as carbon nanotubes in an amount of 0.1 to 3 vol % inclusive and an insulation ceramic material (3) which contains yttrium oxide as the main component, wherein the electrically conductive ceramic material (2) and the insulation ceramic material (3) are adhered to each other in an integrated manner through an adhesive layer (4) which includes an inorganic adhesive material.

A voltage-nonlinear resistor element 10 includes a voltage-nonlinear resistor (referred simply as “resistor”) 20 and a pair of electrodes 14 and 16 between which the resistor 20 is interposed. The resistor 20 has a multilayer structure including a first layer 21 composed primarily of zinc oxide, a second layer 22 composed primarily of zinc oxide, and a third layer 23 composed primarily of a metal oxide other than zinc oxide. The second layer 22 is adjacent to the first layer 21 and has a smaller thickness and a higher volume resistivity than the first layer 21. The third layer 23 is adjacent to the second layer 22.

Disclosed are methods for producing carbon foam in which using the vitrinite reflectance values of coals are used to form a blended coal precursor having a targeted vitrinite reflectance value. The targeted vitrinite reflectance value can be used to create similar carbon foam products from one production batch to the next.

An NTC component comprising a first electrode (1) and a second electrode (2) is specified. The NTC component further comprises an NTC element (3) disposed between the first electrode (1) and the second electrode (2), wherein the NTC element (3) comprises a ceramic having the general composition AB.sub.2O.sub.4, and where A and B each comprise one or more of the materials Mn, Ni, Co and Cu, and B additionally comprises one or more of the materials Fe, Y, Pr, Al, In, Ga and Sb.

Electronic devices are produced from dielectric compositions comprising a mixture of precursor materials that, upon firing, forms a dielectric material comprising a barium-strontium-titanium-tungsten-silicon oxide.

A ceramic waveguide includes: a doped metal oxide ceramic core layer; and at least one cladding layer comprising the metal oxide surrounding the core layer, such that the core layer includes an erbium dopant and at least one rare earth metal dopant being: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, thulium, ytterbium, lutetium, scandium, or oxides thereof, or at least one non-rare earth metal dopant comprising zirconium or oxides thereof. Also included is a quantum memory including: at least one doped polycrystalline ceramic optical device with the ceramic waveguide and a method of fabricating the ceramic waveguide.

An armor component and manufacturing thereof which includes a ceramic hard material, where the hard material has a bulk density that is lower than 3.5 g/cm.sup.3 and includes grains of ceramic material having a Vickers hardness that is higher than 15 GPa, bonded by an bonding matrix, the bonding matrix representing between 20 and 80% by weight of the constituent hard material of the ceramic body, and including alumina, silicon nitride and TiC.sub.xN.sub.1-x crystalline phases, wherein x is included between 0 and 1.

A method for preparing an infrared radiation ceramic material includes mixing and ball milling raw materials of Fe.sub.2O.sub.3, MnO.sub.2 and CuO in a mass ratio to obtain a mixed powder; pressing the mixed powder; adjusting laser spot, laser power and laser sintering time of a laser; irradiating or sintering by a first laser the pressed mixed powder in a crucible for a high-temperature solid-phase reaction to obtain an AB.sub.2O.sub.4 type ferrite powder; obtaining a first mixture by mixing the AB.sub.2O.sub.4 type ferrite powder and a cordierite powder in a mass ratio; adding a sintering aid and a nucleating agent for ball milling; obtaining a second mixture by mixing the first mixture and a binder for aging; pressing the second mixture; and irradiating or sintering the pressed second mixture by a second laser to obtain the infrared radiation ceramic material.