As novel Zintl phases with the LiGaGe structure type, Ca_1−xCe_xAg_1−ySb has shown decent thermoelectric performance as well as complex structure transitions, which are closely related to the Ag defects in the anionic layers. In this report, La/Sr co-doped materials, Ca_1−x−δSr_δLa_xAg_1−ySb (0 ≤ δ ≤ 0.7), were prepared and studied regarding relevant thermoelectric properties. Interestingly, the incorporation of alkaline-earth metal Sr suggested a different structure transition mechanism from the LiGaGe type to the ZrBeSi-type, which seemed closely related to the Sr doping concentrations. Besides, significant enhancement of the thermoelectric performance resulted. For materials with a specific composition of Ca_0.55Sr_0.3La_0.15Ag_0.89Sb, a maximum zT of 0.7 has been achieved at 823 K, which also corresponded to a high average zT value of 0.66 between 774 and 1068 K.

中文翻译：

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结构变换中的Ca _{1- X - δ}锶_δ拉_X银_{1- Ý}的Sb（0≤ δ ≤0.7）和相关的热电性能†

作为具有LiGaGe结构类型的新型Zintl相，Ca _{1- x} Ce _x Ag _{1- y} Sb具有良好的热电性能以及复杂的结构转变，这与阴离子层中的Ag缺陷密切相关。在这份报告中的La / SR共掺杂材料，钙_{1- X - δ}锶_δ拉_X银_{1- Ý}的Sb（0≤ δ≤0.7），并就相关的热电性能进行了研究。有趣的是，碱土金属Sr的掺入提示了从LiGaGe型到ZrBeSi型的不同结构转变机理，这似乎与Sr掺杂浓度密切相关。此外，显着提高了热电性能。对于Ca _0.55 Sr _0.3 La _0.15 Ag _0.89 Sb的特定成分的材料，在823 K处实现的最大zT为0.7，这也对应于774和1068 K之间的0.66的高平均zT值。