Production of hollow germanium alloy quasi-spheres through a coaxial nozzle

Hollow germanium alloy quasi-spheres of diameters 1-2 mm have been produced based on hollow jet instability. The germanium was first melted at around 1273 K and then extruded from a coaxial nozzle into an inert atmosphere by argon supplied to the inner nozzle. The falling spheres were cooled by water spray and collected in a bucket. The spheres had relatively smooth inner and outer surfaces, but were somewhat aspherical. The ex-post characterization of germanium sphere revealed Ge, Fe, Cr and Ni at atomic percentages of 64.04%, 16.21%, 8.55% and 10.30% respectively. (C) 2019 The Japan Society of Applied Physics