A method for producing a single crystal having a diameter of 200 mm or greater in which: (1) a seed crystal is provided; (2) an upper surface of the seed crystal is melted with an infrared ray supplied obliquely from above to create a melt covering the upper surface of the seed crystal; and (3) a powder raw material is supplied from above the seed crystal onto an area of the melt that is 90% or less of a diameter of the seed crystal, and the powder raw material supplied onto the melt is melted with the infrared ray supplied obliquely from above to melt the powder raw material while, simultaneously, a lower surface of the melt is solidified on the seed crystal. The infrared ray is applied to an area of the melt that is within 90% of the diameter of the seed crystal.

A method for producing a single crystal having a diameter of 200 mm or greater in which: (1) a seed crystal is provided; (2) an upper surface of the seed crystal is melted with an infrared ray supplied obliquely from above to create a melt covering the upper surface of the seed crystal; and (3) a powder raw material is supplied from above the seed crystal onto an area of the melt that is 90% or less of a diameter of the seed crystal, and the powder raw material supplied onto the melt is melted with the infrared ray supplied obliquely from above to melt the powder raw material while, simultaneously, a lower surface of the melt is solidified on the seed crystal. The infrared ray is applied to an area of the melt that is within 90% of the diameter of the seed crystal.

Provided are a Ga.sub.2O.sub.3-based single crystal substrate including a Ga.sub.2O.sub.3-based single crystal which has a high resistance while preventing a lowering of crystal quality and a production method therefor. According to one embodiment of the present invention, the production method includes growing the Ga.sub.2O.sub.3-based single crystal while adding a Fe to a Ga.sub.2O.sub.3-based raw material, the Ga.sub.2O.sub.3-based single crystal (5) including the Fe at a concentration higher than that of a donor impurity mixed in the Ga.sub.2O.sub.3-based raw material, and cutting out the Ga.sub.2O.sub.3-based single crystal substrate from the Ga.sub.2O.sub.3-based single crystal (5).

Provided are a Ga.sub.2O.sub.3-based single crystal substrate including a Ga.sub.2O.sub.3-based single crystal which has a high resistance while preventing a lowering of crystal quality and a production method therefor. According to one embodiment of the present invention, the production method includes growing the Ga.sub.2O.sub.3-based single crystal while adding a Fe to a Ga.sub.2O.sub.3-based raw material, the Ga.sub.2O.sub.3-based single crystal (5) including the Fe at a concentration higher than that of a donor impurity mixed in the Ga.sub.2O.sub.3-based raw material, and cutting out the Ga.sub.2O.sub.3-based single crystal substrate from the Ga.sub.2O.sub.3-based single crystal (5).

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.

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.

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.

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.

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.

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.