Synthesis of ordered α-FeSe nanorod array by CVD and its high Tc

Abstract Based on chemical vapor deposition (CVD) in the absence of any template and catalyst, large-scale oriented vertical FeSe nanorod (NR) array (NRA) has been produced. Electron microscopy shows a typical diameter and length of single FeSe NRs are ~ 200 and 600 nm, respectively and electron/X-ray diffraction confirms the single-crystal α-phase. Magnetic measurements reveal these NRAs are superconducting with an onset T c above 16 K, which is much higher than T c of counterpart bulk sample (~ 8 K). Superconducting FeSe NRAs with the T c may open up new possibilities for the fundamental understanding of the effect of dimensionality.