Apparatus and method for production and encapsulation of small particles and thin wires
A method of forming one of a plurality of encapsulated crystalline particles includes feeding a coaxial feed wire downwardly such that a first wire end of the coaxial feed wire is positioned at a heating source. The coaxial feed wire includes a crystalline wire core, and an amorphous shell surrounding the crystalline wire core. The first end of the coaxial feed wire is heated at the heating source, thereby forming a molten pendant drop at the first wire end. The plurality of encapsulated crystalline particles are emitted from the molten pendant drop onto a collector located below the molten pendant drop.
1. An apparatus for depositing forming one of a plurality of encapsulated crystalline particles, comprising:
a coaxial feed wire, comprising:
a crystalline wire core; and
an amorphous shell surrounding the crystalline wire core;
a heating source at which a first wire end of the coaxial feed wire is positioned; and
a collector disposed below the heating source;
wherein heating of the first wire end at the heating source forms a molten pendant drop at the first wire end from which a plurality of encapsulated crystalline particles are emitted onto the collector; and
a pressure controlled chamber at which the coaxial feed wire is disposed upstream of the heating source.
2. The apparatus of claim 1 , further comprising a flow of sheath gas around the coaxial feed wire upstream of the heating source.
3. The apparatus of claim 1 , further comprising a grounded electrode disposed below the molten pendant drop.
4. The apparatus of claim 1 , wherein the plurality of encapsulated crystalline particles are one or more small core particles or thin core wires.
5. The apparatus of claim 4 , wherein the one or more small core particles are less than 1 mm in diameter.
6. The apparatus of claim 4 , wherein the thin core wires are less than 100 μm in diameter.
7. The apparatus of claim 1 , wherein the heating source heats the feed wire by one or more of resistive heating, induction heating, torch heating, laser heating, microwave heating, electron beam heating, or plasma heating.
8. The apparatus of claim 1 , wherein the collector is grounded.
9. An apparatus for forming a plurality of encapsulated particles, comprising:
a coaxial feed wire, comprising:
a crystalline wire core; and
an amorphous shell surrounding the crystalline wire core;
a heating source at which a first wire end of the coaxial feed wire is positioned; and
a collector disposed below the heating source;
wherein heating of the first wire end at the heating source forms a molten pendant drop at the first wire end from which a plurality of encapsulated crystalline particles are emitted onto the collector;
a high voltage source to which a second wire end of the feed wire opposite the first wire end is connected;
wherein the high voltage source applies a voltage in a range of 0-100 kV across the crystalline wire core.