Preparation of Na1+xFe4P12 whiskers by hydrothermal reduction alloying synthesis method

Skutterudite Na1+xFe4P12 whiskers were prepared by a new hydrothermal reduc tion alloying method. The diameter of the whisker is about 0.5-4 mum and it s L/D ratio is about 10-20. Heating temperature and time can control the di ameter and length of the skutterudite whisker. X-ray diffraction (XRD), sca nning electron microscopy (SEM), transmission electron microscope (TEM), el ectronic diffraction (ED), and X-ray fluorescence analysis have been employ ed to characterize the products. XRD and ED revealed that the whiskers obta ined at 200 degreesC are cubic skutterudite with a = 7.7995 Angstrom. X-ray fluorescence analysis proved that there are sodium atoms in the skutterudi te structure. The possible formation mechanism of Na1+xFe4P12 is proposed.