Thermoelectric and mechanical properties on misch metal filled p-type skutterudites Mm{sub 0.9}Fe{sub 4−x}Co{sub x}Sb{sub 12}

Journal Article · Sat Feb 07 00:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4906954· OSTI ID:22413061

Dahal, Tulashi; Jie, Qing; Dahal, Keshab; Lan, Yucheng; Ren, Zhifeng ^[1]; Gahlawat, Sonika; White, Kenneth ^[2]

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1. Department of Physics and Texas Center for Superconductivity, University of Houston, Texas 77204 (United States)
2. Department of Mechanical Engineering, University of Houston, Texas 77204 (United States)

Most of the recent work focused on improving the dimensionless figure-of-merit, ZT, of p-type skutterudites uses one or two fillers to tune the electrical and thermal properties. Considering the fact that the different fillers with varying atomic mass and ionic radii can vibrate with different amplitudes to scatter phonons of different mean free paths, we synthesized misch metal filled p-type skutterudites Mm{sub 0.9}Fe{sub 4−x}Co{sub x}Sb{sub 12} (where Mm is La{sub 0.25}Ce{sub 0.5}Pr{sub 0.05}Nd{sub 0.15}Fe{sub 0.03}, called misch metal). The samples were synthesized by hot pressing nano-powder made by ball milling the annealed ingot of Mm{sub 0.9}Fe{sub 4−x}Co{sub x}Sb{sub 12} with varying concentration of cobalt, x. By tuning the Fe/Co ratio, we achieved a thermal conductivity of ∼2 W m{sup −1} K{sup −1} at room temperature and ∼2.3 W m{sup −1} K{sup −1} at about 530 °C and a power factor of ∼30 μW cm{sup −1} K{sup −2} at about 425 °C in Mm{sub 0.9}Fe{sub 3.1}Co{sub 0.9}Sb{sub 12}, leading to a peak ZT ∼1.1 at about 425 °C. The nano-indentation experiment reveals that hardness and elastic modulus of the material is about 4.2 GPa and 116 GPa, respectively.

• OSTI ID: 22413061
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
ANTIMONIDES
CERIUM COMPOUNDS
COBALT
COBALT COMPOUNDS
CONCENTRATION RATIO
HARDNESS
HOT PRESSING
IRON COMPOUNDS
MEAN FREE PATH
MILLING
MISCH METAL
PHONONS
POWDERS
PRESSURE RANGE GIGA PA
P-TYPE CONDUCTORS
TEMPERATURE RANGE 0273-0400 K
THERMAL CONDUCTIVITY