A compound strontium fluoroborate, nonlinear optical crystal of strontium fluoroborate, preparation method thereof; the chemical formula of the compound is SrB5O7F3, its molecular weight is 310.67, and it is prepared by solid-state reaction; the chemical formula of the crystal is SrB5O7F3, its molecular weight is 310.67, the crystal is of the orthorhombic series, the space group is Ccm21, and the crystal cell parameters are=10.016(6) Å, b=8.654(6)(4) Å, c=8.103(5) Å, Z=4, and V=702.4(8) Å3. A SrB5O7F3 nonlinear optical crystal has uses in the preparation of a harmonic light output when doubling, tripling, quadrupling, quintupling, or sextupling the frequency of a 1064-nm fundamental-frequency light outputted by a Nd:YAG laser, or the generation of a deep-ultraviolet frequency doubling light output lower than 200 nm, or in the preparation of a frequency multiplier, upper or lower frequency converter, or an optical parametric oscillator.

The invention relates to a method for growing a bulk single crystal, wherein the method comprises the steps of inserting a starting material into a crucible, melting the starting material in the crucible by heating the starting material, arranging a thermal insulation lid at a distance above a melt surface of said melt such that at least a central part of the melt surface is covered by the lid, and growing the bulk single crystal from the melt by controllably cooling the melt with the thermal insulation lid arranged above the melt surface.

A production apparatus for a metal oxide single crystal according to the present invention includes a crucible for housing a crystal raw material and a seed crystal, which has a first end and a second end, and in which the crystal raw material is disposed on a first end side, and the seed crystal is disposed on a second end side, a heater that heats the crucible, and a cooling rod, which has a third end and a fourth end, and in which the third end is provided in contact with or in proximity to the second end of the crucible so as to cool the second end by depriving the second end of heat.

A method for manufacturing a blade with a first portion and a second portion, the method includes forming the first portion that includes forming a model of the first portion from removable material, forming a first shell mould from the model of the first portion, and forming the single-crystal or columnar first portion m a first metal alloy in the first shell mould from a single-crystal seed, and forming the second portion in which the second portion is formed on the first portion, and in which the first portion and the second portion are made from different materials, the second portion being polycrystalline and formed from a second metal alloy. The blade includes a single-crystal or columnar first portion made from a first metal alloy and a polycrystalline second portion made from the second metal alloy different from the first metal alloy.

Methods and wafers for low etch pit density, low slip line density, and low strain indium phosphide are disclosed and may include an indium phosphide single crystal wafer having a diameter of 4 inches or greater, having a measured etch pit density of less than 500 cm.sup.−2, and having fewer than 5 dislocations or slip lines as measured by x-ray diffraction imaging. The wafer may have a measured etch pit density of 200 cm.sup.−2 or less, or 100 cm.sup.−2 or less, or 10 cm.sup.−2 or less. The wafer may have a diameter of 6 inches or greater. An area of the wafer with a measured etch pit density of zero may at least 80% of the total area of the surface. An area of the wafer with a measured etch pit density of zero may be at least 90% of the total area of the surface.

A furnace for electromagnetic casting a tubular-shaped silicon ingot is provided. The furnace includes a mold, outer and inner induction coils and a support member. The mold includes an outer crucible and an inner crucible. The outer crucible is annular-shaped. The inner crucible is disposed in the outer crucible and spaced away from the outer crucible to provide a gap between the inner crucible and the outer crucible. The mold is configured to receive granular silicon in the gap. The outer induction coil disposed around the outer crucible. The inner induction coil disposed in the inner crucible. The outer induction coil and the inner induction coil are configured to heat and melt the granular silicon in the mold to form a tubular-shaped silicon ingot. The support member is configured to hold and move a seed relative to the mold during formation of the tubular-shaped silicon ingot on the seed.

A directional solidification casting assembly includes a directional solidification mold having an interior chamber with a shape of an object to be cast using directional solidification of molten metal in a growth direction of the mold and a feed line conduit. The conduit is fluidly coupled with a container source of the molten metal and is coupled with the mold at a gating. The feed line conduit conveys the molten metal into the mold through the gating for directional solidification of the object to be cast in the mold. At least a downstream portion of the feed line conduit that is between the intermediate location of the feed line conduit and the second open end of the feed line conduit is located below the gating along the growth direction of the mold.

The present invention relates to a method of manufacturing polycrystalline silicon ingot using a crucible in which an oxygen exhaust passage is formed by single crystal or polycrystalline rods, the method including the steps of: manufacturing the single crystal or polycrystalline silicon rods each having the shape of a quadrilateral pillar; putting the single crystal or polycrystalline quadrilateral pillar-shaped silicon rods into the crucible in such a manner as to be arranged close to one another along the inner peripheral surface of the crucible to thus form a space portion inside the single crystal or polycrystalline silicon rods, into which silicon chunks are put, and the oxygen exhaust passages between the inner peripheral surface of the crucible and the respective surfaces of the single crystal or polycrystalline silicon rods oriented toward the inner peripheral surface of the crucible; putting the silicon chunks into the space portion of the crucible; and melting and crystallizing the silicon chunks.

Provided is a Mg.sub.2Si single crystal in which generation of low-angle grain boundaries in the crystal is satisfactorily suppressed. A Mg.sub.2Si single crystal, wherein a variation in crystal orientation as measured by XRD is in a range of ±0.020°.

Methods and wafers for low etch pit density, low slip line density, and low strain indium phosphide are disclosed and may include an indium phosphide single crystal wafer having a diameter of 4 inches or greater, having a measured etch pit density of less than 500 cm.sup.−2, and having fewer than 5 dislocations or slip lines as measured by x-ray diffraction imaging. The wafer may have a measured etch pit density of 200 cm.sup.−2 or less, or 100 cm.sup.−2 or less, or 10 cm.sup.−2 or less. The wafer may have a diameter of 6 inches or greater. An area of the wafer with a measured etch pit density of zero may at least 80% of the total area of the surface. An area of the wafer with a measured etch pit density of zero may be at least 90% of the total area of the surface.