Journal of Applied Physics · 2001 · 436 citations · 19 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsMaterials PhysicsSolid State PhysicsHeat ConductionMagnetic Properties Of SolidsMagnetic SusceptibilityThermal Properties Of CeramicsThermal Properties Of MaterialsThermoelectric MaterialsConductionLattice ParametersLattice Thermal ConductivityLattice Thermal TransportSkutteruditesThermal ConductivityThermoelectric Figure Of MeritThermoelectric Properties
Barium-filled skutterudites BayCo4Sb12 with an anomalously large filling fraction of up to y=0.44 have been synthesized. The lattice parameters increase linearly with Ba content. Magnetic susceptibility data show that Ba0.44Co4Sb12 is paramagnetic, which implies that some of the Co atoms in BayCo4Sb12 have acquired a magnetic moment. The presence of the two different valence states of Co (Co3+ and Co2+) leads to the anomalously large barium filling fraction even without extra charge compensation. All samples show n-type conduction. The electrical conductivity increases with increasing the Ba filling fraction. The lattice thermal conductivity of BayCo4Sb12 is significantly depressed as compared to unfilled Co4Sb12. The dimensionless thermoelectric figure of merit, ZT, increases with increasing temperature reaching a maximum value of 1.1 for Ba0.24Co4Sb12 at 850 K.
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High figure of merit in partially filled ytterbium skutterudite materials
George S. Nolas, M. Kaeser, R. T. Littleton et al. · Applied Physics Letters · 2000 · 560 citations