Abstract
Yb14MnSb11 is the most efficient bulk p-type thermoelectric material for high temperature applications. Materials with Y and Sc substitutions in Yb14MnSb11 were made both in Sn-flux and by ball milling. These small 3+ rare earth (RE) cations were introduced with the goal of providing chemical pressure on the structure. The RE3+ cation is smaller than Yb2+ and also donates one additional electron to this p-type semiconductor. In Yb14-x RE x MnSb11 (RE = Sc, Y) the maximum x was about 0.5. X-ray diffraction experiments on the single crystals obtained from Sn-flux showed that Sc preferentially substitutes for Yb(1) and Yb(3), and decreases the size of the unit cell by about 0.3%. Y substitutes on all Yb sites and increases the size of the unit cell by about 0.2%. Samples with Yb14-x RE x MnSb11 (x~0.3) were prepared via powder metallurgy and spark plasma sintering for transport and thermal conductivity measurements. Electron microprobe of the Sc-substituted sample showed small regions (≤1 μm) containing greater amounts of Sc, and X-ray powder diffraction of the ball milled Sc sample could be fitted as phase pure Yb14-x Sc x MnSb11. Y-substituted samples showed larger regions of excess Y in electron microprobe, and small amounts of Yb4Sb3 in X-ray powder diffraction. The Sc sample has slightly reduced carrier concentration over optimized Yb14MnSb11, while the Y samples have even lower carrier concentrations. These carrier concentrations lead to comparable resistivity to Yb14MnSb11 in the Sc-substituted material, and higher resistivities in the Y-substituted material. All materials had similar Seebeck coefficients that slightly exceed Yb14MnSb11 at high temperatures, with the Sc-substituted sample having the highest despite having a higher carrier concentration. Sc-substituted samples also had a slightly higher thermal conductivity over the Y-substituted samples, which had comparable thermal conductivity to Yb14MnSb11. The zT values of the Sc and Y substituted samples are similar (zT1000K~0.8), however below that of Yb14MnSb11 due to the compensation of Seebeck and resistivity.
| Original language | English (US) |
|---|---|
| Journal | Journal of Solid State Chemistry |
| DOIs | |
| State | Accepted/In press - Dec 6 2015 |
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Keywords
- Chemical pressure
- Rare earth compounds
- Thermoelectric material
- Zintl
ASJC Scopus subject areas
- Condensed Matter Physics
- Inorganic Chemistry
- Physical and Theoretical Chemistry
- Ceramics and Composites
- Electronic, Optical and Magnetic Materials
- Materials Chemistry
Cite this
Effects of Sc and Y substitution on the structure and thermoelectric properties of Yb14MnSb11 . / Grebenkemper, Jason H.; Klemenz, Sebastian; Albert, Barbara; Bux, Sabah K.; Kauzlarich, Susan M.
In: Journal of Solid State Chemistry, 06.12.2015.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effects of Sc and Y substitution on the structure and thermoelectric properties of Yb14MnSb11
AU - Grebenkemper, Jason H.
AU - Klemenz, Sebastian
AU - Albert, Barbara
AU - Bux, Sabah K.
AU - Kauzlarich, Susan M.
PY - 2015/12/6
Y1 - 2015/12/6
N2 - Yb14MnSb11 is the most efficient bulk p-type thermoelectric material for high temperature applications. Materials with Y and Sc substitutions in Yb14MnSb11 were made both in Sn-flux and by ball milling. These small 3+ rare earth (RE) cations were introduced with the goal of providing chemical pressure on the structure. The RE3+ cation is smaller than Yb2+ and also donates one additional electron to this p-type semiconductor. In Yb14-x RE x MnSb11 (RE = Sc, Y) the maximum x was about 0.5. X-ray diffraction experiments on the single crystals obtained from Sn-flux showed that Sc preferentially substitutes for Yb(1) and Yb(3), and decreases the size of the unit cell by about 0.3%. Y substitutes on all Yb sites and increases the size of the unit cell by about 0.2%. Samples with Yb14-x RE x MnSb11 (x~0.3) were prepared via powder metallurgy and spark plasma sintering for transport and thermal conductivity measurements. Electron microprobe of the Sc-substituted sample showed small regions (≤1 μm) containing greater amounts of Sc, and X-ray powder diffraction of the ball milled Sc sample could be fitted as phase pure Yb14-x Sc x MnSb11. Y-substituted samples showed larger regions of excess Y in electron microprobe, and small amounts of Yb4Sb3 in X-ray powder diffraction. The Sc sample has slightly reduced carrier concentration over optimized Yb14MnSb11, while the Y samples have even lower carrier concentrations. These carrier concentrations lead to comparable resistivity to Yb14MnSb11 in the Sc-substituted material, and higher resistivities in the Y-substituted material. All materials had similar Seebeck coefficients that slightly exceed Yb14MnSb11 at high temperatures, with the Sc-substituted sample having the highest despite having a higher carrier concentration. Sc-substituted samples also had a slightly higher thermal conductivity over the Y-substituted samples, which had comparable thermal conductivity to Yb14MnSb11. The zT values of the Sc and Y substituted samples are similar (zT1000K~0.8), however below that of Yb14MnSb11 due to the compensation of Seebeck and resistivity.
AB - Yb14MnSb11 is the most efficient bulk p-type thermoelectric material for high temperature applications. Materials with Y and Sc substitutions in Yb14MnSb11 were made both in Sn-flux and by ball milling. These small 3+ rare earth (RE) cations were introduced with the goal of providing chemical pressure on the structure. The RE3+ cation is smaller than Yb2+ and also donates one additional electron to this p-type semiconductor. In Yb14-x RE x MnSb11 (RE = Sc, Y) the maximum x was about 0.5. X-ray diffraction experiments on the single crystals obtained from Sn-flux showed that Sc preferentially substitutes for Yb(1) and Yb(3), and decreases the size of the unit cell by about 0.3%. Y substitutes on all Yb sites and increases the size of the unit cell by about 0.2%. Samples with Yb14-x RE x MnSb11 (x~0.3) were prepared via powder metallurgy and spark plasma sintering for transport and thermal conductivity measurements. Electron microprobe of the Sc-substituted sample showed small regions (≤1 μm) containing greater amounts of Sc, and X-ray powder diffraction of the ball milled Sc sample could be fitted as phase pure Yb14-x Sc x MnSb11. Y-substituted samples showed larger regions of excess Y in electron microprobe, and small amounts of Yb4Sb3 in X-ray powder diffraction. The Sc sample has slightly reduced carrier concentration over optimized Yb14MnSb11, while the Y samples have even lower carrier concentrations. These carrier concentrations lead to comparable resistivity to Yb14MnSb11 in the Sc-substituted material, and higher resistivities in the Y-substituted material. All materials had similar Seebeck coefficients that slightly exceed Yb14MnSb11 at high temperatures, with the Sc-substituted sample having the highest despite having a higher carrier concentration. Sc-substituted samples also had a slightly higher thermal conductivity over the Y-substituted samples, which had comparable thermal conductivity to Yb14MnSb11. The zT values of the Sc and Y substituted samples are similar (zT1000K~0.8), however below that of Yb14MnSb11 due to the compensation of Seebeck and resistivity.
KW - Chemical pressure
KW - Rare earth compounds
KW - Thermoelectric material
KW - Zintl
UR - http://www.scopus.com/inward/record.url?scp=84961226203&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84961226203&partnerID=8YFLogxK
U2 - 10.1016/j.jssc.2016.03.015
DO - 10.1016/j.jssc.2016.03.015
M3 - Article
AN - SCOPUS:84961226203
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
SN - 0022-4596
ER -