Methods of making dispersion-hardened platinum compositions include A) producing a melt having at least 70 wt. % platinum, up to 29.95 wt. % of one or more of rhodium, gold, iridium and palladium, between 0.05 wt. % and 1 wt. % of oxidizable non-precious metals in the form of zirconium, yttrium and scandium, and, as the remainder, platinum including impurities, wherein the ratio of zirconium to yttrium in the melt is in a range of from 5.9:1 to 4.3:1 and the ratio of zirconium to scandium in the melt is at least 17.5:1, B) hardening the melt to form a solid body, C) processing the solid body to form a volume body, and D) oxidizing the non-precious metals contained in the volume body by a heat treatment in an oxidizing medium over a time period of at least 48 hours at a temperature of at least 750° C.

A quartz glass crucible including a bottom portion, a curved portion, and a straight body portion, where the quartz glass crucible includes an outer layer including opaque quartz glass containing bubbles therein, and an inner layer including transparent quartz glass, the outer layer includes a plurality of layers in a part of the straight body portion, out of the plurality of layers, one layer having a devitrification spot number of 50/cm.sup.3 or more and 70/cm.sup.3 or less when the quartz glass crucible is heated at 1600° C. for 24 hours, and a layer positioned inwards of the devitrifiable layer in a thickness direction of the quartz glass crucible is a low devitrification layer having a spot number of 2/cm.sup.3 or less when the quartz glass crucible is heated at 1600° C. for 24 hours. This provides a quartz glass crucible suppressed from deformation due to heating and excessive progression of devitrification.

A method of producing high strength shaped alumina by feeding alumina power into an agglomerator having a shaft with mixers able to displace the alumina power along the shaft, spraying a liquid binder onto the alumina power as it is displaced along the shaft to form a shaped alumina, and calcining the shaped alumina. The shaped alumina produced having a loose bulk density of greater than or equal to 1.20 g/ml, a surface area less than 10 m.sup.2/g, impurities of less than 5 ppm of individual metals and less than 9 ppm of impurities in total, and/or crush strength of greater than 12,000 psi.

An apparatus for manufacturing compound single crystal includes a crystal growth section to hold a seed crystal, a gas supply section to supply a metal-contained gas and a reactant gas toward the seed crystal, and a heating section to heat the seed crystal and a metal source. The gas supply section includes a crucible holding the metal source, a carrier gas supply unit, and a reactant gas supply unit. A porous baffle plate is provided in an opening of the crucible. The porous baffle plate satisfies a relationship of 80%≤(1−V.sub.H/V.sub.B)×100<100% and a relationship of 0.0003<a.sup.2/L<1.1. V.sub.B is an apparent volume of the porous baffle plate, V.sub.H is a total volume of the through-holes contained in the porous baffle plate, “a” is a diameter of the through-hole, and L is a length of the through-hole.

Produced is a large single crystal with no crystal grain boundary, which is a high-quality single crystal that has a uniform composition in both the vertical and horizontal directions at an optimum dopant concentration. Provided is a single-crystal production equipment including, at least: a granular raw material supply apparatus which supplies a certain amount of a granular raw material downward; a granular raw material melting apparatus which heats and melts the granular raw material and supplies the thus obtained raw material melt downward; and a crystallization apparatus which allows a single crystal to precipitate out of a mixed melt that is formed upon receiving a melt formed by irradiating an infrared ray from a first infrared ray irradiation equipment to the upper surface of a seed single crystal and the raw material melt supplied from the granular raw material melting apparatus.

An apparatus for producing an ingot includes a crucible body having an opening and in which raw materials are accommodated, and a lid assembly located at the opening and having a portion fixed to the crucible body. The lid assembly includes a placement hole having open upper and lower ends, a frame member arranged along a periphery of the opening while surrounding a periphery of the placement hole, and a core member located in the placement hole and movable upward and downward with respect to the frame member.

Conditioning of tungsten pentachloride to form specific crystalline phases is disclosed. The specific crystalline phases permit stable vapor pressures over extended periods of time during vapor deposition and etching processes.

A silicon carbide crystal growing apparatus includes a physical vapor transport unit and an atomic layer deposition unit. The physical vapor transport unit has a crystal growing furnace configured to grow a silicon carbide crystal in an internal space of the crystal growing furnace. The atomic layer deposition unit is coupled to the crystal growing furnace and configured to perform an atomic doping operation on the silicon carbide crystal. A silicon carbide crystal growing method is also provided.

A preparation apparatus for uniform silicon carbide crystals comprises a circular cylinder, a doping tablet, and a plate to stabilize and control the supply of dopants. The accessory does not participate in the reaction in the growth chamber but maintains its efficacy during growth. Finally, a single semi-insulating silicon carbide crystal with uniform electrical characteristics can be obtained.

A measurement method and a measurement apparatus are capable of measuring the transmittance of a quartz crucible accurately. A measurement method includes: emitting a parallel light from a light source disposed on a side of one wall surface of a quartz crucible toward a predetermined measurement point of the quartz crucible; measuring reception levels of light transmitted through the quartz crucible at a plurality of positions by disposing a detector at the plurality of positions on a circle centered around an exit point of the parallel light on the other wall surface of the quartz crucible; and calculating a transmittance of the quartz crucible at the predetermined measurement point based on a plurality of the reception levels of the transmitted light measured at the plurality of positions.