Sublimation-Condensation of Multiscale Tellurium Structures

This paper presents a simple process for making tellurium (Te) nano- and microtubes of widely varying dimensions with the multiscale processing (MSP) technique. In this process, the Te metal was placed in a borosilicate glass reaction vessel and a fused quartz substrate was added. The vessel was evacuated and sealed under vacuum with a torch. Then, the vessel was heated under a temperature gradient where the portion of the tube with the substrate was under a decreasing temperature gradient Scanning and transmission electron microscopies have shown that multifaceted crystalline tubes have been formed extending from nano- up to micrometer scale with diameters ranging from 51.2 +/- 5.9 to 1042 +/- 134 nm between temperatures of 157 and 224 degrees C, respectively. One-dimensional tubular features are seen at lower temperatures and three-dimensional features at the higher temperatures. These features were characterized with X-ray diffraction and found to be trigonal Te with space group P3121. Our results show that the MSP can adequately be described using a simple Arrhenius equation.