Abstract:
A layer of HgCdTe (15) epitaxially grown onto a crystalline support (10), e.g., of sapphire of GaAs. A CdTe substrate (5) is epitaxially grown to a thickness of between 1 micron and 5 microns on the support (10). A HgTe source (3) is spaced from the CdTe substrate (5) a distance of between 0.1 mm and 10 mm. The substrate (5) and source (3) are heated together in a thermally insulating, reusable ampoule (17) within a growth temperature range of between 500.degree. C. and 625.degree. C. for a growth step having a duration of between 5 minutes and 4 hours. Then an interdiffusion step is performed, in which the source (3) and substrate (5) are cooled within a temperature range of between 400.degree. C. and 500.degree. C. for a time of between 1 hour and 16 hours. In a first growth step embodiment, the source (3) and substrate (5) are isothermal. In a second growth step embodiment, the source (3) and substrate (5) are non-isothermal. Means are disclosed for preventing contamination of the reactants during HgTe (3) synthesis, and for polishing the HgCdTe layer (15).
Abstract:
A layer of HgCdTe (15) is epitaxially grown on a crystalline support (10). A single crystal CdTe substrate (5) is first epitaxially grown to a thickness of between 1 micron and 5 microns onto the support (10). Then a HgTe source (3) is spaced from the CdTe substrate (5) a distance of between 0.1 mm and 10 mm. The substrate (5) and source (3) are heated together in a thermally insulating, reusable ampoule (17) within a growth temperature range of between 500.degree. C. and 625.degree. C. for a growth time of between 5 minutes and 13 hours. In a first growth step embodiment, the source (3) and substrate (5) are non-isothermal. In a second growth step embodiment, the source (3) and substrate (5) are isothermal. Then an optional interdiffusion step is performed, in which the source (3) and substrate (5) are cooled within a temperature range of between 400.degree. C. and 500.degree. C. for a time of between 1 hour and 16 hours. Means are disclosed for preventing contamination of the reactants during HgTe (3) synthesis, and for polishing the finished HgCdTe layer (15).
Abstract:
A layer of HgCdTe (15) epitaxially grown on a crystalline support (10). A single crystal CdTe substrate (5) is first epitaxially grown to a thickness of between 1 micron and 5 microns onto the support (10). Then a HgTe source (3) is spaced from the CdTe substrated (5) a distance of between 0.1 mm and 10 mm. The substrate (5) and source (3) are heated together in a thermally insulating, reusable ampoule (17) within a growth temperature range of between 500.degree. C. and 625.degree. C. for a growth time of between 5 minutes and 13 hours. In a first growth step embodiment, the source (3) and substrate (5) are isothermal. In a second growth step embodiment, the source (3) and substrate (5) are non-isothermal. Then an optional interdiffusion step is performed, in which the source (3) and substrate (5) are cooled within a temperature range of between 400.degree. C. and 500.degree. C. for a time of between 1 hour and 16 hours. Means are disclosed for preventing contamination of the reactants during HgTe (3) synthesis, and for polishing the finished HgCdTe layer (15).
Abstract:
A layer of HgCdTe (15) is epitaxially grown onto a CdTe substrate (5). A HgTe source (3) is spaced from the CdTe substrate (5) a distance of between 0.1 mm and 10 mm. The substrate (5) and source (3) are heated within a temperature range of between 500.degree. C. and 625.degree. C. for a processing step having a duration of between 5 minutes and 4 hours. During at least 5 minutes of this processing step, the substrate (5) is made to have a greater temperature than the source (3). Preferably the substrate (5) is never at a lower temperature than the source (3). The source (3) and substrate (5) are heated together in a thermally insulating, reusable ampoule (17). The CdTe substrate (5) is preferably a thin film epitaxially grown on a support (10) e.g., of sapphire or GaAs. When support (10) is not used, the CdTe substrate (5) is polished; and sublimation and solid state diffusion growth mechanisms are present in the growth of the HgCdTe (15). Means are disclosed for preventing contamination of the reactants during HgTe (3) synthesis and bulk CdTe wafer (5) polishing.
Abstract:
A process is described for synthesizing a porous, crystalline material having the framework structure of ZSM-12 of the formula: (n)YO2:X2O3 wherein X is a trivalent element, Y is a tetravalent element and n is between about 80 and about 250. In the process, a mixture capable of forming said material is prepared comprising sources of alkali or alkaline earth metal (M), an oxide of trivalent element (X), an oxide of tetravalent element (Y), hydroxyl ions (OFF), water and tetraethylammonium cations (R), wherein said mixture has a composition, in terms of mole ratios, within the following ranges: YO2/X2O3=100 to 300; H2O/YO2=5 to 15; OH−/YO2=0.10 to 0.30; M/YO2=0.05 to 0.30; and R/YO2=0.10 to 0.20. The mixture is reacted at a temperature of at least about 300° F. (149° C.) for a time of less than about 50 hours to form crystals of the crystalline material and the crystalline material is then recovered.
Abstract translation:描述了一种用于合成具有下式的ZSM-12的骨架结构的多孔结晶材料的方法:(n)YO 2:X 2 O 3其中X是三价元素,Y是四价元素,n在约80和约250之间 在该方法中,制备能够形成所述材料的混合物,其包含碱金属或碱土金属(M),三价元素(X)的氧化物,四价元素(Y)的氧化物,羟基离子(OFF), 水和四乙基铵阳离子(R),其中所述混合物的摩尔比为组成,在以下范围内:YO 2 / X 2 O 3 = 100至300; H2O / YO2 = 5〜15; OH- / YO 2 = 0.10〜0.30; M / YO2 = 0.05〜0.30; R / YO2 = 0.10〜0.20。 混合物在至少约300°F(149℃)的温度下反应约少于约50小时,形成晶体,然后回收结晶物质。
Abstract:
This invention relates to hydrocracking catalysts utilizing stabilized aggregates of small primary crystallites of zeolite Y that are clustered into larger secondary particles. At least 80% of the secondary particles may comprise at least 5 primary crystallites. The size of the primary crystallites may be at most about 0.5 micron, or at most about 0.3 micron, and the size of the secondary particles may be at least about 0.8 micron, or at least about 1.0 μm. The silica to alumina ratio of the resulting stabilized aggregated Y zeolite may be 4:1 or more. This invention also relates to the use of such catalysts in hydrocracking processes for the conversion of heavy oils into lighter fuel products. The invention is particularly suited for the selective production of diesel range products from gas oil range feedstock materials under hydrocracking conditions.
Abstract:
Methods for growing HgCdTe (15) upon a CdTe substrate (5) using a HgTe source (3) and close-spaced vapor phase epitaxy (CSVPE). A processing temperature T of between 520.degree. C. and 625.degree. C. is employed over a processing time t of between approximately 1/4 and 4 hours. The thickness A of the grown HgCdTe (15) is a linear function of processing time t. The mole fraction x of cadmium in the HgCdTe (15) is a linear function of temperature T and an exponential function of the mole fraction y of mercury in the source (3). The lower the relative amount of mercury in the source (3), the greater the relative amount of mercury in the end product (15), and vice versa. Any crystal plane and any axial orientation of the CdTe substrate (5) can be used without affecting the rate of growth of the HgCdTe (15), the single crystal nature of the HgCdTe (15), or the mirror-like finish of its surface. At least 90% of the transition between the CdTe substrate (5) and the grown HgCdTe layer (15) occurs within the first 20% of the HgCdTe layer (15); for distances greater than this away from the substrate (5), the HgCdTe (15) exhibits a substantially uniform x.
Abstract:
This invention relates to hydrocracking catalysts utilizing stabilized aggregates of small primary crystallites of zeolite Y that are clustered into larger secondary particles. At least 80% of the secondary particles may comprise at least 5 primary crystallites. The size of the primary crystallites may be at most about 0.5 micron, or at most about 0.3 micron, and the size of the secondary particles may be at least about 0.8 micron, or at least about 1.0 μm. The silica to alumina ratio of the resulting stabilized aggregated Y zeolite may be 4:1 or more. This invention also relates to the use of such catalysts in hydrocracking processes for the conversion of heavy oils into lighter fuel products. The invention is particularly suited for the selective production of diesel range products from gas oil range feedstock materials under hydrocracking conditions.
Abstract:
This invention relates to stabilized aggregates of small primary crystallites of zeolite Y that are clustered into larger secondary particles. At least 80% of the secondary particles may comprise at least 5 primary crystallites. The size of the primary crystallites may be at most about 0.5 micron, or at most about 0.3 micron, and the size of the secondary particles may be at least about 0.8 micron, or at least about 1.0 μm. The silica to alumina ratio of the resulting stabilized aggregated Y zeolite may be 4:1 or more.
Abstract:
A process for producing ZSM-48 comprises crystallizing an aqueous reaction mixture comprising at least one source of silica, at least one source of alumina, at least one source of hydroxyl ions, at least one source of diquaternary alkylammonium, R2+, ions having the formula: (CH3)3N+(CH2)5N+(CH3)3 and optionally ZSM-48 seed crystals, wherein said reaction mixture has a composition including the following molar ratios: R2+:SiO2less than 0.1 SiO2:Al2O3less than 100 OH−:SiO2less than 0.2.