摘要:
An apparatus including a crucible, an energy source, and a controller is provided. The crucible may be sealed to a nitrogen-containing gas, and may be chemically inert to at least ammonia at a temperature in a range of about 400 degrees Celsius to about 2500 degrees Celsius. The energy source may supply thermal energy to the crucible. The controller may control the energy source to selectively direct sufficient thermal energy to a predefined first volume within the crucible to attain and maintain a temperature in the first volume to be in a range of from about 400 degrees Celsius to about 2500 degrees Celsius. The thermal energy may be sufficient to initiate, sustain, or both initiate and sustain growth of a crystal in the first volume. The first temperature in the first volume may be controllable separately from a second temperature in another volume within the crucible. The first temperature and the second temperature differ from each other. Associated methods are provided.
摘要:
A single crystal or quasi-single crystal including one or more Group III material and an impurity. The impurity includes one or more elements from Group IA, Group IIA, Groups IIIB to VIIB, Group VIII, Group IB, Group IIB, or Group VIIA elements of the periodic table of elements. A composition for forming a crystal is also provided. The composition includes a source material comprising a Group III element, and a flux comprising one or more of P, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Pd, Ag, Hf, Ta, W, Pt, Au, Hg, Ge, or Sb; or the flux may comprise a rare earth metal.
摘要:
A fused quartz article, such as a muffle tube or crucible, with enhanced creep resistance. The enhanced creep resistance is the result of controlled devitrification of the fused quartz article. Controlled devitrification is achieved by coating the article with a colloidal silica slurry doped with metal cations, such as barium, strontium, and calcium. The metal cations in the slurry promote nucleation and growth of cristobalite crystals into the fused quartz at temperatures in the range from about 1000° C. to about 1600° C. The cristobalite has significantly. higher viscosity, and therefore greater creep resistance at elevated temperatures, than fused quartz. Methods for applying a doped coating to a fused quartz article and improving the creep resistance of a fused quartz article are also disclosed.
摘要:
A chemical vapor deposition apparatus comprises a heating element capable of emitting electromagnetic radiation; a retort positioned relative to the heating element to receive the electromagnetic radiation; an encasing member at least partially disposed around the retort, the encasing member comprising a material that is at least partially transparent to the electromagnetic radiation; a plenum defined at least in part by an inner surface of the encasing member and an outer surface of the retort; and a furnace box at least partially disposed around the encasing member and the retort, and housing the heating element.
摘要:
A silica deposition tube is fused in a deuterium (D2) gas atmosphere and optionally baked in a deuterium (D2) gas atmosphere to substantially reduce the hydrogen content in the tube for decreased fiber attenuation. Alternatively, raw silica material is pre-treated in D2 gas followed by fusing of the raw silica tube in a D2 gas environment.
摘要:
A coating structure including an outer coating comprising aluminum; and an interlayer disposed between a substrate and the outer coating is provided. The interlayer may include a rare earth metal, a transition metal, or a noble metal. The interlayer may have one or more property of being less responsive to halogen etching relative to the outer coating; having a coefficient of thermal expansion that is greater than the coefficient of thermal expansion of the substrate and less than the coefficient of thermal expansion of the outer coating or vice versa; having a color different from the color of the outer coating; having a electrical conductivity different from the electrical conductivity of the outer coating. A method of making is article is provided. The method may include securing an interlayer to a substrate surface, and securing an outer coating to a surface of the interlayer opposite the substrate.
摘要:
An apparatus for manufacture of quartz crucibles comprising a hollow mold having a bottom wall portion and a side wall portion and defining a hollow space therein. The walls of the mold include a plurality of openings to facilitate gas passage therethrough. A rotatable support of the mold is provided to rotate the mold about a vertical axis. A vacuum is applied through the walls of the mold to draw quartz particles against the walls and remove gas. A shroud surrounds at least a portion of the hollow mold; at least one gas inlet positioned to provide a gas to a space between the shroud and the mold. A housing overlaps at least a portion of the shroud and the hollow mold. At least one gas outlet is positioned to exhaust gas which may exit the space between the shroud and the mold. Alternatively, or in addition to the outlet, a space may be provided between the housing (hood) and the shroud to facilitate gas discharge. In manufacturing a crucible in this apparatus, the gas flow can be balanced so the in-flow rate of control gas is in excess of the exhaust rate from the controlled atmosphere via the outlet or space.