Thermoelectric properties of Fe1-xNixSb3 ribbons

This paper deals with the microstructures and thermoelectric properties of Fe1-xNixSb3 ribbons between x=0 and 1.0. The ribbons were: fabricated by casting on a rotating copper roll with the surface velocity of 10m/s, and then annealed for 3.6ks at 873K. The microstructures were investigated by means of X-ray diffraction measurements and transmission electron microscopic observations. The CoAs3 type of structure, namely skutterudite structure, appeared as well as the other structures of FeSb2, NiSb2 and Sb below x=0.45 and above 0.55. Only the skutterudite appeared and the other structures disappeared between x=0.45 and 0.55, The thermoelectromotive force and electrical resistivity were measured under a vacuum from 300K to 670K. The thermoelectromotive force was of p-type of semiconductor for x<0.5 and of n-type for x>0.5, The electrical resistivity recorded a maximum at x=0.5. The curve of electrical resistivity versus x was asynmetric at x=0.5. The electrical resistivity was larger for x<0.5 than for x>0.5 at the same deviation from x=0.5. The power factor, which was estimated from the thermoelectromotive force and electrical resistivity, reached to maximums at x=0.4 and x=0.6, and was small at x=0.5 at 300K.