The lithium composite oxide single crystal has a chemical composition represented by Li.sub.7-3x-w-vGa.sub.xLa.sub.3Zr.sub.2-w-vTa.sub.WNb.sub.vO.sub.12 (0.02x<0.5, 0W1.0, 0V1.0, and 0.05W+V1.0), which belongs to a space group I-43d in a cubic system and has a garnet structure.

The lithium composite oxide single crystal has a chemical composition represented by Li.sub.7-3x-w-vGa.sub.xLa.sub.3Zr.sub.2-w-vTa.sub.WNb.sub.vO.sub.12 (0.02x<0.5, 0W1.0, 0V1.0, and 0.05W+V1.0), which belongs to a space group I-43d in a cubic system and has a garnet structure.

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 and contains only a small number of negative crystals and exsolution lamellae. A single-crystal production equipment includes at least: a quartz crucible in which a seed crystal is placed on its bottom; a powder raw material supply apparatus which supplies a powder raw material into the quartz crucible; and an infrared ray irradiation apparatus which applies an infrared ray to the powder raw material supplied into the quartz crucible from the powder raw material supply apparatus.

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 and contains only a small number of negative crystals and exsolution lamellae. A single-crystal production equipment includes at least: a quartz crucible in which a seed crystal is placed on its bottom; a powder raw material supply apparatus which supplies a powder raw material into the quartz crucible; and an infrared ray irradiation apparatus which applies an infrared ray to the powder raw material supplied into the quartz crucible from the powder raw material supply apparatus.

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.

Methods for purifying reaction precursors used in the synthesis of inorganic compounds and methods for synthesizing inorganic compounds from the purified precursors are provided. Also provided are methods for purifying the inorganic compounds and methods for crystallizing the inorganic compounds from a melt. and X-ray detectors incorporating the crystals of the inorganic compounds are also provided.

A purification apparatus and a method of purifying hot zone parts are provided. The purification apparatus is configured to remove impurities attached on at least one hot zone part. The purification apparatus includes a crystal high temperature furnace, an enclosed box disposed in the crystal high temperature furnace, an outer tube connected to the crystal high temperature furnace and the enclosed box, an inner tube disposed in the outer tube, and a gas inlet cover connected to the outer tube. The crystal high temperature furnace includes a furnace body, a furnace cover, and a thermal field module disposed in the furnace body. The gas inlet cover is configured to input a noble gas into the enclosed box through the inner tube, and the thermal field module is configured to heat the noble gas so that the impurities are heated and vaporized through the noble gas.

A purification apparatus and a method of purifying hot zone parts are provided. The purification apparatus is configured to remove impurities attached on at least one hot zone part. The purification apparatus includes a crystal high temperature furnace, an enclosed box disposed in the crystal high temperature furnace, an outer tube connected to the crystal high temperature furnace and the enclosed box, an inner tube disposed in the outer tube, and a gas inlet cover connected to the outer tube. The crystal high temperature furnace includes a furnace body, a furnace cover, and a thermal field module disposed in the furnace body. The gas inlet cover is configured to input a noble gas into the enclosed box through the inner tube, and the thermal field module is configured to heat the noble gas so that the impurities are heated and vaporized through the noble gas.

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 and contains only a small number of negative crystals and exsolution lamellae. A single-crystal production equipment includes at least: a quartz crucible in which a seed crystal is placed on its bottom; a powder raw material supply apparatus which supplies a powder raw material into the quartz crucible; and an infrared ray irradiation apparatus which applies an infrared ray to the powder raw material supplied into the quartz crucible from the powder raw material supply apparatus.