Efficient dopants for ZrNiSn-based thermoelectric materials

• Published in: Journal of physics. Condensed matter Vol. 11; no. 7; pp. 1697 - 1709
• Main Authors: Hohl, Heinrich, Ramirez, Art P, Goldmann, Claudia, Ernst, Gabriele, Wölfing, Bernd, Bucher, Ernst
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 22.02.1999; Institute of Physics
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic conduction in metals and alloys; Electronic transport in condensed matter; Exact sciences and technology; Metals. Metallurgy; Physics; Thermoelectric and thermomagnetic effects; Temperature dependence; Nickel alloys; Intermetallic compounds; Ternary alloys; Doped materials; Seebeck effect; Experimental study; Thermoelectric properties; Materials preparation; Tin alloys; Impurity site; Thermal conductivity; Carrier density; Figure of merit; Transition element alloys; Semiconductor metal transition; Zirconium alloys
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/11/7/004

Four efficient n-type dopants have been found for ZrNiSn-based thermoelectric materials. These are Nb or Ta at the zirconium sites, and Sb or Bi at the tin sites. No suitable dopant was found for the nickel sites. In a (Zr sub 0.5 Hf sub 0.5 ) sub 0.99 Ta sub 0.01 NiSn alloy, a power factor of S exp 2 sigma = 22 mu W K exp -2 cm exp -1 and a thermal conductivity of K = 5.4 mult 10 exp -2 W K exp -1 cm exp -1 were measured at 300 K, resulting in a dimensionless figure of merit ZT = 0.12. These values are increased to S exp 2 sigma approx = 40 mu W K exp -2 cm exp -1 and ZT approx = 0.5 at 700 K. Materials discussed: doped and undoped ANiSn (A=Ti, Zr, Hf) compounds.