Jeffrey S. Dyck

Anomalous barium filling fraction and n-type thermoelectric performance of BayCo4Sb12

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.

Thermoelectric properties of the n-type filled skutterudite Ba0.3Co4Sb12 doped with Ni

Synthesis and electrical and thermal transport properties are reported for several filled skutterudite compounds doped with Ni: Ba0.3NixCo4−xSb12 with 0<x<0.2. Divalent Ba readily fills the cages of the skutterudite structure and is effective in reducing the thermal conductivity of the structure. The presence of a small amount of Ni increases the electron concentration, further reduces the thermal conductivity, and enhances the thermoelectric power factor. Hall mobility studies indicate that the addition of Ni to the system has the effect of increasing the relative strength of ionized impurity scattering as compared to acoustic phonon scattering. These results suggest that doping with Ni is an attractive avenue to optimization of filled skutterudites. The dimensionless thermoelectric figure of merit ZT was observed to increase from a value of 0.8 at 800 K for Ba0.3Co4Sb12 to a value of 1.2 for the sample with x=0.05. These materials show considerable potential as n-type legs in thermoelectric power genera...

Thermoelectric properties of the n-type filled skutterudite Ba0.3Co4Sb12Ba0.3Co4Sb12 doped with Ni

Synthesis and electrical and thermal transport properties are reported for several filled skutterudite compounds doped with Ni: Ba0.3NixCo4−xSb12 with 0<x<0.2. Divalent Ba readily fills the cages of the skutterudite structure and is effective in reducing the thermal conductivity of the structure. The presence of a small amount of Ni increases the electron concentration, further reduces the thermal conductivity, and enhances the thermoelectric power factor. Hall mobility studies indicate that the addition of Ni to the system has the effect of increasing the relative strength of ionized impurity scattering as compared to acoustic phonon scattering. These results suggest that doping with Ni is an attractive avenue to optimization of filled skutterudites. The dimensionless thermoelectric figure of merit ZT was observed to increase from a value of 0.8 at 800 K for Ba0.3Co4Sb12 to a value of 1.2 for the sample with x=0.05. These materials show considerable potential as n-type legs in thermoelectric power genera...

Enhancing thermoelectric performance of ternary nanocrystals through adjusting carrier concentration.

The carrier concentration of chemically synthesized Bi(2)Te(3)-based nanocrystals (NCs) is for the first time reported to be adjusted by forming ternary Bi(2-x)Sb(x)Te(3) NCs (x = 0.02, 0.05, 0.10, 0.20, 0.50, and 1.50) through partial substitution of Bi with Sb. Carrier concentrations of ternary Bi(2-x)Sb(x)Te(3) NCs were successfully adjusted by a factor of more than 10 controlled by the stoichiometric partial Sb/Bi substitution level. The power factors of the stoichiometric ternary Bi(2-x)Sb(x)Te(3) NCs improved three times compared to the parent Bi(2)Te(3) due to the carrier concentration adjustment.

Low-temperature ferromagnetic properties of the diluted magnetic semiconductor Sb2-x Crx Te3 .

We report on magnetic and electrical transport properties of

Toward high-performance nanostructured thermoelectric materials: The progress of bottom-up solution chemistry approaches

{\mathrm{Sb}}_{2\ensuremath{-}x}{\mathrm{Cr}}_{x}{\mathrm{Te}}_{3}

Highly anisotropic crystal growth and thermoelectric properties of K2Bi8−xSbxSe13 solid solutions: Band gap anomaly at low x

single crystals with

High-temperature thermoelectric properties of n-type BayNixCo4-xSb12.

0\ensuremath{\leqslant}x\ensuremath{\leqslant}0.095

Anomalous barium filling fraction and n-type thermoelectric performance of Ba{sub y}Co{sub 4}Sb{sub 12}

over temperatures from

Low-temperature transport properties of polycrystalline Ba 8 Ga 16 Sn 30

2\phantom{\rule{0.3em}{0ex}}\mathrm{K}