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.

Disclosed are a Li.sup.+ doped metal halide scintillation crystal with a zero-dimensional perovskite structure, a preparation method and use thereof. The scintillation crystal has a chemical formula of Cs.sub.3-xCu.sub.2I.sub.5:xLi, where x is in a range of 0.003 to 0.3. The method for preparing the scintillation crystal comprises the steps of: weighting and fully mixing a CuI powder, a CsI powder and a LiI powder in a molar ratio of 2:(3-x):x in an inert atmosphere to obtain a mixed powder, and growing into the scintillation crystal from the mixed powder by Bridgman Stockbarger method. After excited, the scintillation crystal could emit a broadband blue light in a range of 350-550 nm, with an intensity much higher than that of the original pure component crystal. The existence of Li.sup.+ further expands the application of the scintillation crystals from X/γ-ray detection to neutron detection.

A gas phase nanowire growth apparatus including a reaction chamber, a first input and a second input. The first input is located concentrically within the second input and the first and second input are configured such that a second fluid delivered from the second input provides a sheath between a first fluid delivered from the first input and a wall of the reaction chamber.

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.

Provided is a cadmium zinc telluride (CdZnTe) single crystal including a main surface that has a high mobility lifetime product (μτ product) in a wide range, wherein the main surface has an area of 100 mm.sup.2 or more and has 50% or more of regions where the μτ product is 1.0×10.sup.−3 cm.sup.2/V or more based on the entire main surface, and a method for effectively producing the same.

In a crystal growth furnace having an array of vertically arranged heaters to provide controlled heating zones within a chamber, and a crucible for holding crystal material, wherein the crystal is grown vertically through the heating zones, the improvement includes a laser mounted outside the chamber which radiates a beam of energy to locally melt precipitates and inclusions. The furnace includes a mechanism to position the laser vertically to, at or near the interface between the formed crystal and crystal melt material above the formed crystal. The crystal material can be CdZnTe.

The present invention relates to a substrate-triggered single crystal superalloy directional solidification process, including: (1) preparing a single crystal substrate material having crystallographic characteristics that match crystallographic characteristics of the single crystal superalloy; (2) fabricating a single crystal substrate chilling plate using the obtained single crystal substrate material; and (3) applying the obtained single crystal substrate chilling plate in a directional solidification apparatus, and then preparing a single crystal alloy product by performing superalloy melting and directional solidification. Compared with grain selector method and seeding with grain selector method, in addition to control the crystallographic orientation of the single crystal superalloy precisely, the present invention could reduce the height of block and the whole mold through canceling the spiral grain selector, significantly improve the axial heat dissipation and temperature gradient at the solid-liquid interface, and then reduce the occurrence of freckles and stray grains near platform.

The present invention discloses a directional solidification method for a superalloy single crystal blade based on solid-liquid interface steady control. The method establishes effective criteria for withdrawal speed adjustment, i.e. the related position between a macro solid-liquid interface and a thermal baffle, the range between the dendrite tips at the solid-liquid interface, and the difference between the advance speed of the macro solid-liquid interface and the withdrawal speed. With these criteria, the advance of the solid-liquid interface during directional solidification is simulated and a withdrawal speed curve v(t) for the solid-liquid interface steady advancement was obtained. And then, the single crystal blade was prepared.