Thermoelectric properties of Ti1+xS2 prepared by CS2 sulfurization
Thermoelectric properties of Ti1+xS2 prepared by CS2 sulfurization
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DOI：
10.1016/j.actamat.2012.09.035
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发表时间：
2012-12
期刊：
影响因子：
9.4
通讯作者：
M. Ohta;Shuhei Satoh;Toshihiro Kuzuya;S. Hirai;Masaru Kunii;A. Yamamoto
中科院分区：
文献类型：
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作者：
M. Ohta;Shuhei Satoh;Toshihiro Kuzuya;S. Hirai;Masaru Kunii;A. Yamamoto
采用CS2气体在1073 K下对TiO 2粉体进行硫化处理，制备了TiS 2粉体。由于CS2气体是TiO 2的强硫化剂，因此CS2硫化可以在低温下进行。将制备的TiS_2粉末与硫粉按1：0.04的质量比混合，在真空中于50 MPa的单轴压力下于973 K下烧结1h。在TiS 2粉末中加入少量硫粉可防止烧结体中的硫不足，从而形成接近化学计量比的Ti1.008S2组合物。X-射线衍射图谱表明，晶体的ab-轴优先取向垂直于压制方向。在300- 723 K温度范围内测量了具有近化学计量比和贫硫（富钛）成分的取向TiS_2烧结体的Seebeck系数、电阻率和热导率。通过防止缺硫和形成取向织构，提高了热电优值ZT。Ti 1.008S2在663 K时，垂直于压制轴方向的ZT最高，为0.34。
Titanium disulfide (TiS2) powder was prepared by sulfurizing TiO2powder with CS2gas at 1073K for 4h. Because CS2gas is a powerful sulfurizing agent for TiO2, CS2sulfurization can be performed at a low temperature. The TiS2powder thus prepared was first mixed with sulfur powder in a mass ratio of 1:0.04 and pressure sintered at 973K for 1h under a uniaxial pressure of 50MPa in vacuum. The addition of a small amount of sulfur powder to the TiS2powder prevents sulfur deficiency in the sintered compact, resulting in the formation of a near-stoichiometric Ti1.008S2composition. X-ray diffraction patterns show that the crystalline ab-axis is preferentially oriented perpendicular to the pressing direction. The Seebeck coefficient, electrical resistivity and thermal conductivity of the oriented TiS2sintered compacts with near-stoichiometric and sulfur-poor (titanium-rich) compositions were measured in the temperature range 300–723K. The thermoelectric figure of merit ZT was enhanced by prevention of sulfur deficiency and formation of the oriented texture. The highest ZT of 0.34 was observed at 663K in Ti1.008S2for the direction perpendicular to the pressing axis.