Fabrication of α-TeO2 smooth and beaded microwires by thermal evaporation method

Long α-TeO2 microwires were synthesized in high yield on quartz substrate by vapor transport process, using Te powder as the source material and oxygen (O2) as a carrier gas. Scanning electron microscope (SEM), X-Ray diffraction (XRD), transmission electron microscopy (TEM) and selected area diffraction patterns (SAD) were employed to characterize the microstructures obtained at different growth time steps in order to propose a possible growth mechanism of microwires. Irregular microparticles were first formed on the quartz substrate surface and then they acted as self-catalytic center for the growth of smooth microwires with diameters in the range 2–4 μm and lengths up to 300 μm. As heating time proceeded, the surface of the microwires was gradually covered by microparticles, till they covered the wires along their whole length. Interestingly, microwires with a segmented morphology were also observed.

► Long α-TeO2 microwires were synthesized by vapor transport process. ► The microstructures obtained at different growth time steps were characterized. ► A possible growth mechanism for smooth and beaded microwires was proposed. ► Microwires with a segmented morphology were also observed.