A device for producing a tubular single crystal comprises a crucible, a heating means, a die disposed in the crucible, having an annular slit, and a pulling-up means. The upper surface of the die includes an upward slope that increases in height from the annular slit to an inner diameter side and an outer diameter side, respectively, progressing away from the annular slit, wherein the maximum height of the slope on the inner diameter side (H1) is greater than the maximum height of the slope on the outer diameter side (H2) and the difference (H1−H2) is 0.1 mm or more and less than 7.5 mm.

A device for producing a tubular single crystal comprises a crucible, a heating means, a die disposed in the crucible, having an annular slit, and a pulling-up means. The upper surface of the die includes an upward slope that increases in height from the annular slit to an inner diameter side and an outer diameter side, respectively, progressing away from the annular slit, wherein the maximum height of the slope on the inner diameter side (H1) is greater than the maximum height of the slope on the outer diameter side (H2) and the difference (H1−H2) is 0.1 mm or more and less than 7.5 mm.

A method for growing on a substrate strongly aligned uniform cross-section semiconductor composite nanocolumns is disclosed. The method includes: (a) forming faceted pyramidal pits on the substrate surface; (b) initiating nucleation on the facets of the pits; and; (c) promoting the growth of nuclei toward the center of the pits where they coalesce with twinning and grow afterwards together as composite nanocolumns. Multi-quantum-well, core-shell nanocolumn heterostructures can be grown on the sidewalls of the nanocolumns. Furthermore, a continuous semiconductor epitaxial layer can be formed through the overgrowth of the nanocolumns to facilitate fabrication of high-quality planar device structures or for light emitting structures.

A method for growing on a substrate strongly aligned uniform cross-section semiconductor composite nanocolumns is disclosed. The method includes: (a) forming faceted pyramidal pits on the substrate surface; (b) initiating nucleation on the facets of the pits; and; (c) promoting the growth of nuclei toward the center of the pits where they coalesce with twinning and grow afterwards together as composite nanocolumns. Multi-quantum-well, core-shell nanocolumn heterostructures can be grown on the sidewalls of the nanocolumns. Furthermore, a continuous semiconductor epitaxial layer can be formed through the overgrowth of the nanocolumns to facilitate fabrication of high-quality planar device structures or for light emitting structures.

A manufacturing method includes providing a material that includes a plurality of particles and a binder that is uncured. The method also includes forming a first article from the material including curing the binder to bind a collection of the particles together into the first article. Furthermore, the method includes encasing at least a portion of the first article with an outer member. The outer member defines an internal cavity that corresponds to the first article. Additionally, the method includes heating the outer member and the first article to melt the collection of particles into a molten mass within the internal cavity of the outer member. Moreover, the method includes solidifying the molten mass within the outer member to form a second article. The second article corresponds to at least a portion of the internal cavity of the outer member.

In one aspect, the present disclosure pertains to methods of making various noble metal nanoprisms, e.g., gold nanoprisms. In various aspects, the methods can comprise incubating, under dark conditions, a growth solution comprising: (a) a plurality of gold seed structures; (b) a gold precursor, and (c) a photocatalytic intermediary, such that during the incubating step multiply-twinned gold seed structures in the growth solution are preferentially enlarged. The disclosed methods can comprise separating the multiply-twinned gold seed structures from the growth solution based upon the size of the gold seed structures to produce an enriched growth solution. In some aspects, the methods comprise irradiating the enriched growth solution to produce the gold nanoprisms. In some aspects, the disclosed nanoprisms comprise silver.

In one aspect, the present disclosure pertains to methods of making various noble metal nanoprisms, e.g., gold nanoprisms. In various aspects, the methods can comprise incubating, under dark conditions, a growth solution comprising: (a) a plurality of gold seed structures; (b) a gold precursor, and (c) a photocatalytic intermediary, such that during the incubating step multiply-twinned gold seed structures in the growth solution are preferentially enlarged. The disclosed methods can comprise separating the multiply-twinned gold seed structures from the growth solution based upon the size of the gold seed structures to produce an enriched growth solution. In some aspects, the methods comprise irradiating the enriched growth solution to produce the gold nanoprisms. In some aspects, the disclosed nanoprisms comprise silver.

Core-shell nanostructures with platinum overlayers conformally coating palladium nano-substrate cores and facile solution-based methods for the preparation of such core-shell nanostructures are described herein. The obtained Pd@Pt core-shell nanocatalysts showed enhanced specific and mass activities towards oxygen reduction, compared to a commercial Pt/C catalyst.

Core-shell nanostructures with platinum overlayers conformally coating palladium nano-substrate cores and facile solution-based methods for the preparation of such core-shell nanostructures are described herein. The obtained Pd@Pt core-shell nanocatalysts showed enhanced specific and mass activities towards oxygen reduction, compared to a commercial Pt/C catalyst.

A manufacturing method includes providing a material that includes a plurality of particles and a binder that is uncured. The method also includes forming a first article from the material including curing the binder to bind a collection of the particles together into the first article. Furthermore, the method includes encasing at least a portion of the first article with an outer member. The outer member defines an internal cavity that corresponds to the first article. Additionally, the method includes heating the outer member and the first article to melt the collection of particles into a molten mass within the internal cavity of the outer member. Moreover, the method includes solidifying the molten mass within the outer member to form a second article. The second article corresponds to at least a portion of the internal cavity of the outer member.