High Temperature Thermoelectric Properties of the Solid-Solution Zintl Phase Eu₁₁Cd_6–xZn_xSb₁₂

Abstract

To investigate the quality of each sample after hot pressing, synchrotron powder XRD (SPXRD) was utilized. Representative patterns of the x p = 1, 2, 5, and 6 samples of Eu 11 Cd 6-x Zn x Sb 12 solid solutions are shown in Figure S1. The best profile matching was achieved by using the crystal structures solved for crystals of each reaction. The corresponding calculated patterns are shown as orange dashed lines overlaid on each observed pattern, shown in black. This profile matching results in the best figures of merit when the main phase with 11-6-12 structure and the minor phase related to the 9-4-9 structure were used in refinement. Samples with x p = 3 and 4 showed high volume fractions of 9-4-9 structure resulting to not be considered in this study. Lebail profile matching on the powder patterns of the other samples with x p = 1, 2, 5, and 6 showed a minor contribution from 9-4-9 structure.Zn Lα X-ray maps given by EMPA on single crystals and pressed pellets are provided in Figure S2. The average compositions with standard deviations in parentheses are also listed below the corresponding images. There is good agreement between the compositions obtained from single crystal X-ray diffraction and from EMPA. Zn distribution on all samples show homogenous samples except in x p = 2 pellet that two regions of high Zn and low Zn contents are making larger standard deviations.

Zintl-phase Eu 2 ZnSb 2 : A promising thermoelectric material with ultralow thermal conductivity

“…It is noteworthy that high carrier mobility (μ) and low lattice thermal conductivity (κ L ) will lead to a large B value. (38). These properties point to the promising TE performance of Eu 2 ZnSb 2 .…”

“…. 2B, in the temperature range from 300 to 823 K, Eu 2 Zn 0.98 Sb 2 outperforms the current popular optimized p-type Zintl TE materials, including the 3-1-3 (Ca 2.97 Na 0.03 AlSb 3 ) -, 11-6-12 (Eu 11 Cd 4.5 Zn 1.5 Sb 12 )-, 1-2-2 (Ca 0.25 Yb 0.75 Zn 2 Sb 2 ) -, and 5-2-6 (Ca 4.75 Na 0.25 Al 2 Sb 6 )-types, among others(24,31,(37)(38)(39)(40), suggesting that it is a promising medium-temperature TE material.…”

Promising Zintl-Phase Thermoelectric Compound SrAgSb

“…Figure b displays the comparison of the ZT values for Sr 1.01 AgSb with some other optimized Zintl compounds. The Sr 1.01 AgSb sample in this work shows comparable performance among other p-type Zintl TE materials, including Eu 2 ZnSb 2 , Eu 5 In 1.9 Zn 0.1 Sb 6 , Ca 2.97 Na 0.03 AlSb 3 , and Eu 11 Cd 4.5 Zn 1.5 Sb 12 , − suggesting that SrAgSb is a promising medium-temperature TE material.…”

“…(a) Temperature-dependent ZT values of Sr x AgSb ( x = 1, 1.01, 1.02, and 1.03). (b) Temperature-dependent ZT values of some p-type Zintl-phase TE materials. ,− …”

Hierarchical Chemical Bonds Contributing to the Intrinsically Low Thermal Conductivity in α‐MgAgSb Thermoelectric Materials

“…The typical examples include filled skutterudites and clathrate compounds . Alternatively, high zT can also be realized in TE materials with intrinsically low lattice thermal conductivity, originating from complex crystal structures, strong anharmonicity, liquid‐like behavior, or mosaic microstructure . Understanding the determining factors for low κ l for particular compounds, and furthermore, the underlying physical and chemical nature are crucial for the design of new materials with low κ l and high TE efficiency.…”