Synthesis and Thermoelectric Properties in the 2D Ti1 – xNbxS3 Trichalcogenides

Materials

Patrick R. N. Misse²  David Berthebaud²  Oleg I. Lebedev²  Antoine Maignan²  Emmanuel Guilmeau¹ 

[1]Laboratoire CRISMAT, UMR 6508 CNRS/ENSICAEN, 6 bd Maréchal Juin, Caen Cedex 4 14050, France

关键词: sulfur;    transition metal sulfides;    niobium;    titanium trisulfide;    thermoelectric;    electrical properties;    thermal conductivity;    Seebeck coefficient;   

DOI  :  10.3390/ma8052514

来源: mdpi

【 摘 要 】

A solid solution of Ti_{1 − x}Nb_xS₃ composition (x = 0, 0.05, 0.07, 0.10) was synthesized by solid-liquid-vapor reaction followed by spark plasma sintering. The obtained compounds crystallize in the monoclinic ZrSe₃ structure type. For the x = 0.07 sample, a mixture of both A and B variants of the MX₃ structure is evidenced by transmission electron microscopy. This result contrasts with those of pristine TiS₃, prepared within the same conditions, which crystallizes as a large majority of A variant. Thermoelectric properties were investigated in the temperature range 323 to 523 K. A decrease in the electrical resistivity and absolute value of the Seebeck coefficient is observed when increasing x due to electron doping. The lattice component of the thermal conductivity is effectively reduced by the Nb for Ti substitution through a mass fluctuation effect and/or a disorder effect created by the mixture of both A and B variants. Due to the low carrier concentration and the semiconductor character of the doped compounds, the too low power factor values leads to ZT values that remain smaller by a factor of 50 than those of the TiS₂ layered compound.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.