Abstract: Continuous casting mold is provided having a mold copper plate having plural separate portions filled with foreign metal formed by filling concave grooves formed on the inner wall surface of the mold copper plate and having a diameter of 2 mm to 20 mm in the inner wall surface at least in the region from a meniscus to a position located 20 mm or more lower than the meniscus with the foreign metal whose thermal conductivity is 80% or less or 125% or more of the mold copper plate, the ratio of the Vickers hardness HVc of the mold copper plate to the Vickers hardness HVm of the filling metal satisfies expression (1), and the ratio of the thermal expansion coefficient ?c of the mold copper plate and the thermal expansion coefficient ?m of the filling metal satisfies expression (2). 0.3?HVc/HVm?2.3??(1), 0.7??c/?m?3.

Abstract: According to the invention, a device and a method for producing materials having a monocrystalline or multicrystalline structure are provided, in which a container is arranged between two pressure regions and the setting of the height of the melt in the container takes place via the setting of the differential pressure between the pressure regions. As a result, even particulate material can be fed continuously to the container and melted uniformly. Delivery material with high purity can also be pulled out of the container.

Abstract: A method for fabricating ion exchange waveguides, such as lithium niobate or lithium tantalate waveguides in optical modulators and other optical waveguide devices, utilizes pressurized annealing to further diffuse and limit exchange of the ions and includes ion exchanging the crystalline substrate with a source of ions and annealing the substrate by pressurizing a gas atmosphere containing the lithium niobate or lithium tantalate substrate above normal atmospheric pressure, heating the substrate to a temperature ranging from about 150 degrees Celsius to about 1000 degrees Celsius, maintaining pressure and temperature to effect greater ion diffusion and limit exchange, and cooling the structure to an ambient temperature at an appropriate ramp down rate. In another aspect of the invention a powder of the same chemical composition as the crystalline substrate is introduced into the anneal process chamber to limit the crystalline substrate from outgassing alkaline earth metal oxide during the anneal period.

Abstract: A method for making a free-standing, single crystal, gallium nitride (GaN) wafer includes forming a single crystal GaN layer directly on a single crystal LiAlO2 substrate using a gallium halide reactant gas, and removing the single crystal LiAlO2 substrate from the single crystal GaN layer to make the free-standing, single crystal GaN wafer. Forming the single crystal GaN layer may comprise depositing GaN by vapor phase epitaxy (VPE) using the gallium halide reactant gas and a nitrogen-containing reactant gas. Because gallium halide is used as a reactant gas rather than a metal organic reactant such as trimethygallium (TMG), the growth of the GaN layer can be performed using VPE which provides commercially acceptable rapid growth rates. In addition, the GaN layer is also devoid of carbon throughout. Because the GaN layer produced is high quality single crystal, it may have a defect density of less than about 107 cm−2.

Abstract: In a monocrystal producing device using a pulling-down method, a raw material melt 5m is continuously supplied into a crucible 2 to grow a crystal 18 by supplying a powdery raw material 5p onto a premelt plate 3 inside an electric furnace 10 with a powdery raw material supplying device 20 and melting the powdery raw material 5p on the premelt plate 3 to generate the raw material melt 5m, and causing this raw material melt 5m to drop out inside the crucible 2. A dry air is introduced into the powdery raw material 5p inside the powdery raw material tank 6 to prevent moisture of the raw material powder 5p. A transferring tube 9 for transferring the raw material 5m is cooled to prevent the filling in the transferring tube 9 based on melting of the powdery raw material 5p. This makes it possible to produce a monocrystal having a stable chemical composition, a large diameter, and a long size at a low price.

Abstract: A process is disclosed for producing an integrated composite oxide single crystal body composed of a core portion made of an oxide single crystal and a clad portion integrated with the core portion and made of another oxide single crystal having a composition different from that of the oxide single crystal constituting the core portion, the process comprising the steps of: (1) preparing a first melt in a first crucible by melting a first material for a first oxide single crystal to constitute the core portion inside the first crucible, (2) preparing a second melt inside a second crucible by melting a second material for a second oxide single crystal to constitute the clad portion inside the second crucible, (3) contacting a seed crystal to the first and second melts, (4) pulling down the first melt through a pull-out opening of the first crucible, (5) pulling down the second melt through a pull-out opening of the second crucible and contacting the pulled-down second melt with a pulled-down portion of the firs

Abstract: When producing an oxide-series single crystal by continuously pulling downwardly by .mu. pulling down method, the composition of the single crystal can properly and quickly controlled to continuously produce the single crystal of a constant composition by changing the pulling rate of the single crystal. Preferably, the pulling rate is 20-300 mm/hr, and the pulling rate is decreased with the proceeding of growing of the single crystal.

Abstract: The process includes processing a molten phase of semiconductor material ering a solid phase of the material and having a free surface opposite this solid phase, into which, during the crystallization procedure, energy is radiated and material is fed in in granular form, which material floats and is melted. As a result, at the opposite solid/liquid interface, material grows on the solid phase which is drawn downwards in accordance with the growth rate. The process allows mono- or polycrystalline rods or blocks to be obtained. The main advantages of the process are that it can be carried out without melting vessels, it is possible to use granular material, and the energy balance is favorable because of the small amounts of melt.