GeO2 nanowires and nanoneedles grown by thermal deposition without a catalyst

Thermal treatment of compacted GeO2 powder under argon flow leads to the growth of a dense distribution of microwires and nanowires on the sample surface. Extended treatment causes the formation of more complex structures, including arrays of nanoneedles. Enhanced cathodoluminescence emission is associated with the wires and needles, which show a component at 2.72 eV not observed. for the untreated material.