title: Invited article: A round robin test of the uncertainty on the measurement of the thermoelectric dimensionless figure of merit of Co0.97Ni0.03Sb3.
abstract: A round robin test aiming at measuring the high-temperature thermoelectric properties was carried out by a group of European (mainly French) laboratories (labs). Polycrystalline skutterudite Co0.97Ni0.03Sb3 was characterized by Seebeck coefficient (8 labs), electrical resistivity (9 labs), thermal diffusivity (6 labs), mass volume density (6 labs), and specific heat (6 labs) measurements. These data were statistically processed to determine the uncertainty on all these measured quantities as a function of temperature and combined to obtain an overall uncertainty on the thermal conductivity (product of thermal diffusivity by density and by specific heat) and on the thermoelectric figure of merit ZT. An increase with temperature of all these uncertainties is observed, in agreement with growing difficulties to measure these quantities when temperature increases. The uncertainties on the electrical resistivity and thermal diffusivity are most likely dominated by the uncertainty on the sample dimensions. The temperature-averaged (300-700 K) relative standard uncertainties at the confidence level of 68% amount to 6%, 8%, 11%, and 19% for the Seebeck coefficient, electrical resistivity, thermal conductivity, and figure of merit ZT, respectively. Thermal conductivity measurements appear as the least accurate. The moderate value of the temperature-averaged relative expanded (confidence level of 95%) uncertainty of 17% on the mean of ZT is essential in establishing Co0.97Ni0.03Sb3 as a high temperature standard n-type thermoelectric material.
authors: Institut de Chimie et Matériaux Paris-Est, UMR CNRS-UPEC 7182, 2-8, rue Henri Dunant, 94320 Thiais, France.
authors: E
authors: E
authors: Alleno
authors: SP2M, ICMMO (CNRS UMR 8182), Université Paris-Sud, 91405 Orsay, France.
authors: D
authors: D
authors: Bérardan
authors: SP2M, ICMMO (CNRS UMR 8182), Université Paris-Sud, 91405 Orsay, France.
authors: C
authors: C
authors: Byl
authors: Institut Jean Lamour, UMR 7198 CNRS-Université de Lorraine, Parc de Saurupt, 54042 Nancy Cedex, France.
authors: C
authors: C
authors: Candolfi
authors: Laboratoire CRISMAT, UMR6508 CNRS-ENSICAEN, 6 Bd du Maréchal Juin, 14050 Caen Cedex, France.
authors: R
authors: R
authors: Daou
authors: ICMCB, CNRS and Université de Bordeaux, UPR 9048, 33600 Pessac, France.
authors: R
authors: R
authors: Decourt
authors: Laboratoire CRISMAT, UMR6508 CNRS-ENSICAEN, 6 Bd du Maréchal Juin, 14050 Caen Cedex, France.
authors: E
authors: E
authors: Guilmeau
authors: Laboratoire CRISMAT, UMR6508 CNRS-ENSICAEN, 6 Bd du Maréchal Juin, 14050 Caen Cedex, France.
authors: S
authors: S
authors: Hébert
authors: Institute of Physics of ASCR, v.v.i, Na Slovance 2, 182 21 Praha 8, Czech Republic.
authors: J
authors: J
authors: Hejtmanek
authors: Institut Jean Lamour, UMR 7198 CNRS-Université de Lorraine, Parc de Saurupt, 54042 Nancy Cedex, France.
authors: B
authors: B
authors: Lenoir
authors: Institut Jean Lamour, UMR 7198 CNRS-Université de Lorraine, Parc de Saurupt, 54042 Nancy Cedex, France.
authors: P
authors: P
authors: Masschelein
authors: Institut Jean Lamour, UMR 7198 CNRS-Université de Lorraine, Parc de Saurupt, 54042 Nancy Cedex, France.
authors: V
authors: V
authors: Ohorodnichuk
authors: ICMCB, CNRS and Université de Bordeaux, UPR 9048, 33600 Pessac, France.
authors: M
authors: M
authors: Pollet
authors: Empa-Swiss Federal Laboratories for Materials Science and Technology, Materials for Energy Conversion, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
authors: S
authors: S
authors: Populoh
authors: Institut Charles Gerhardt, UMR 5253, CNRS-Université Montpellier 2, Place Eugène Bataillon, 34095 Montpellier cedex 5, France.
authors: D
authors: D
authors: Ravot
authors: Institut de Chimie et Matériaux Paris-Est, UMR CNRS-UPEC 7182, 2-8, rue Henri Dunant, 94320 Thiais, France.
authors: O
authors: O
authors: Rouleau
authors: Laboratoire de Thermoélectricité, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble, France.
authors: M
authors: M
authors: Soulier