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Vol.57, No.4, 264 ~ 270, 2019
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| Title |
| Thermoelectric Properties of MnSi1.74-1.75:Gem Prepared by Solid-State Reaction and Hot Pressing |
| In-jae Lee , Sol-bin Park , Soon-chul Ur , Kyung-wook Jang , Il-ho Kim |
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| Abstract |
| Higher manganese silicides (HMSs) MnSi1.74-1.75:Gem (m = 0.01-0.04) were prepared by solid-state reaction and hot pressing. The major phases of the HMSs were Mn27Si47 or Mn4Si7, and a small quantity of Si remained, but the intermetallic compound MnSi was not formed. The lattice constant increased with the substitution of Ge at Si sites. As the Ge content increased, the electrical conductivity increased, and the Seebeck coefficient decreased. The power factor was increased by Ge doping; however, the thermal conductivity also increased. Therefore, the dimensionless figure of merit (ZT) could not be increased significantly by Ge doping. For MnSi1.74:Gem, a maximum ZT of 0.36 was obtained at 823 K for MnSi1.74:Ge0.03; for MnSi1.75:Gem, a maximum ZT of 0.32 was achieved at 823 K for MnSi1.75:Ge0.01.
(Received January 2, 2019; Accepted February 25, 2019) |
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| Key Words |
| thermoelectric, higher manganese silicide, HMS, doping, solid-state reaction, hot pressing |
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