No abstract

Polycrystalline samples of R(4)Sb(3) (R = La, Ce, Sm and Yb) and Yb(4-x)R'(x)Sb(3) (R' = Sm and La) have been quantitatively synthesized by high-temperature reaction. They crystallize in the anti-Th(3)P(4) structure type (I43d, no. 220). Structural and chemical characterizations have been performed by X-ray diffraction and electron microscopy with energy dispersive X-ray analysis. Powders have been densified by spark plasma sintering (SPS) at 1300 degrees C under 50 MPa of pressure. Transport property measurements show that these compounds are n-type with low Seebeck coefficient except for Yb(4)Sb(3) that shows a typical metallic behavior with hole conduction. By partially substituting Yb by a trivalent rare earth we successfully improved the thermoelectric figure of merit of Yb(4-x)R'(x)Sb(3) up to 0.75 at 1000 degrees C.

which crystallizes in the anti-Th 3 P 4 structure type (I-43d no. 220), were synthesized via high-temperature reaction. Structural and chemical characterization were performed by x-ray diffraction and electronic microscopy with energy-dispersive x-ray analysis. Pucks were densified by spark plasma sintering. Transport property measurements showed that these compounds are n-type with low Seebeck coefficients, except for Yb 4 Sb 3 , which shows semimetallic behavior with hole conduction above 523 K. By partially substituting Yb by a trivalent rare earth we successfully improved the thermoelectric figure of merit of Yb 4 Sb 3 up to 0.7 at 1273 K.