Using processes disclosed herein, materials and structures are created and used. For example, processes can include melting boron nitride or amorphous carbon into an undercooled state followed by quenching. Exemplary new materials disclosed herein can be ferromagnetic and/or harder than diamond. Materials disclosed herein may include dopants in concentrations exceeding thermodynamic solubility limits. A novel phase of solid carbon has structure different than diamond and graphite.

FZ single crystals are pulled by melting a polycrystal with electromagnetic melting apparatus and then recrystallizing. First, a lower end of the polycrystal is melted; second, a monocrystalline seed is attached to the lower end of the polycrystal and melted beginning from an upper end thereof; third, between a lower section of the seed and the polycrystal, a thin neck is formed whose diameter (d.sub.D) is smaller than that (d.sub.I) of the seed; and fourth, between the thin neck section and the polycrystal, a conical section is formed. Before the conical growth, a switchover position (h) of the polycrystal, the position at which the rate of polycrystal movement relative to the melting apparatus is to be reduced is determined, and the rate is reduced, in amount when the switchover position (h) is reached.

FZ single crystals are pulled by melting a polycrystal with electromagnetic melting apparatus and then recrystallizing. First, a lower end of the polycrystal is melted; second, a monocrystalline seed is attached to the lower end of the polycrystal and melted beginning from an upper end thereof; third, between a lower section of the seed and the polycrystal, a thin neck is formed whose diameter (d.sub.D) is smaller than that (d.sub.I) of the seed; and fourth, between the thin neck section and the polycrystal, a conical section is formed. Before the conical growth, a switchover position (h) of the polycrystal, the position at which the rate of polycrystal movement relative to the melting apparatus is to be reduced is determined, and the rate is reduced, in amount when the switchover position (h) is reached.

A method for producing or repairing a three-dimensional work piece, the method comprising the following steps: providing at least one substrate (15); depositing a first layer of a raw material powder onto the substrate (15); and irradiating selected areas of the deposited raw material powder layer with an electromagnetic or particle radiation beam (22) in a site selective manner in accordance with an irradiation pattern which corresponds to a geometry of at least part of a layer of the three-dimensional work piece to be produced, wherein the irradiation is controlled so as to produce a metallurgical bond between the substrate (15) and the raw material powder layer deposited thereon. Moreover, a use and apparatus are likewise disclosed.

A method for producing or repairing a three-dimensional work piece, the method comprising the following steps: providing at least one substrate (15); depositing a first layer of a raw material powder onto the substrate (15); and irradiating selected areas of the deposited raw material powder layer with an electromagnetic or particle radiation beam (22) in a site selective manner in accordance with an irradiation pattern which corresponds to a geometry of at least part of a layer of the three-dimensional work piece to be produced, wherein the irradiation is controlled so as to produce a metallurgical bond between the substrate (15) and the raw material powder layer deposited thereon. Moreover, a use and apparatus are likewise disclosed.

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 which includes, at least: a raw material supply apparatus which supplies a granular raw material to a melting apparatus positioned therebelow; the melting apparatus heats and melts the granular raw material to generate a raw material melt and supplies the raw material melt into a single-crystal production crucible positioned therebelow; and a crystallization apparatus which includes the single-crystal production crucible in which a seed single crystal is placed on the bottom, and a first infrared ray irradiation equipment which irradiates an infrared ray to the upper surface of the seed single crystal in the single-crystal production crucible, and the single-crystal production equipment is configured such that the raw material melt is dropped into a melt formed by irradiating the upper surface of the seed single crystal with the infrared ray, and a single crystal is allowed to precipitate out of the thus formed mixed melt.

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 which includes, at least: a raw material supply apparatus which supplies a granular raw material to a melting apparatus positioned therebelow; the melting apparatus heats and melts the granular raw material to generate a raw material melt and supplies the raw material melt into a single-crystal production crucible positioned therebelow; and a crystallization apparatus which includes the single-crystal production crucible in which a seed single crystal is placed on the bottom, and a first infrared ray irradiation equipment which irradiates an infrared ray to the upper surface of the seed single crystal in the single-crystal production crucible, and the single-crystal production equipment is configured such that the raw material melt is dropped into a melt formed by irradiating the upper surface of the seed single crystal with the infrared ray, and a single crystal is allowed to precipitate out of the thus formed mixed melt.

A transparent complex oxide sintered body is manufactured by sintering a compact in an inert atmosphere or vacuum, and HIP treating the sintered compact, provided that the compact is molded from a source powder based on a rare earth oxide: (Tb.sub.xY.sub.1-x).sub.2O.sub.3 wherein 0.4x0.6, and the compact, when heated in air from room temperature at a heating rate of 15 C./min, exhibits a weight gain of at least y% due to oxidative reaction, y being determined by the formula: y=2x+0.3. The sintered body has a long luminescent lifetime as a result of controlling the valence of Tb ion.

A transparent complex oxide sintered body is manufactured by sintering a compact in an inert atmosphere or vacuum, and HIP treating the sintered compact, provided that the compact is molded from a source powder based on a rare earth oxide: (Tb.sub.xY.sub.1-x).sub.2O.sub.3 wherein 0.4x0.6, and the compact, when heated in air from room temperature at a heating rate of 15 C./min, exhibits a weight gain of at least y% due to oxidative reaction, y being determined by the formula: y=2x+0.3. The sintered body has a long luminescent lifetime as a result of controlling the valence of Tb ion.

A laser heated pedestal growth system includes two lasers having output beams that are combined with a beam combiner to produce a single beam. A growth chamber that includes a final focusing mirror for receiving and focusing the single beam of the lasers onto a tip of a feed material to create a molten zone in a focal region. A feed transport mechanism is adapted for transporting a feed material through the growth chamber and into the molten zone. An opposing seed transport mechanism is adapted for withdrawing a seed material from the growth chamber. An imaging system is adapted for capturing an image of the molten zone within the growth chamber. A controller in communication with the feed transport mechanism, the seed transport mechanism, one of the two lasers, and the imagining system is adapted to control and stabilize a fiber growth process by controlling the feed transport mechanism, the seed transport mechanism, and the power of the combined laser beam.