Thermoelectric properties of Ln2-xBixRu2O7 pyrochlores (Ln = Nd and Yb)

• Published in: Materials letters Vol. 51; no. 4; pp. 347 - 350
• Main Authors: ZHOU, Yuqin, MATSUBARA, Ichiro, FUNAHASHI, Ryoji, SODEOKA, Satoshi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 2001
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity phenomena in semiconductors and insulators; Electronic transport in condensed matter; Exact sciences and technology; Physics; Thermoelectric and thermomagnetic effects; Pyrochlore; Temperature dependence; Inorganic compounds; Electrical conductivity; Neodymium compounds; Transition element compounds; Composition effect; Seebeck effect; Ionic radius; Ytterbium compounds; Rare earth compounds; Experimental study; Hopping conduction; Ruthenates; Thermoelectric power; Bismuth compounds; Quaternary compounds; Semiconductor metal transition
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/S0167-577X(01)00317-2

The pyrochlore ruthenates Ln2-xBixRu2O7 (Ln = Nd and Yb, x = 1 and 0.6) were synthesised and their thermoelectric properties were studied from room temperature to 1000 K. The samples showed metallic-like resistivity temperature behaviour (except Yb2-xBixRu2O7). Their resistivity increased with the x values while their Seebeck coefficients (S) were not sensitive to the x values. Although the S of the Nd-system samples was almost the same as that of the Yb-system samples, the resistivity of the former was less than that of the latter. It indicated that the Nd-system samples had higher thermoelectric power factors than Yb-system samples. The resistivity, S and power factor of NdBiRu2O7 at 1000 K was 1.5 m ohm cm, 35 microV/K and 0.8 x 10 exp(-4) W/mK2, respectively. 20 refs.