As novel Zintl phases with the LiGaGe structure type,Ca1−xCexAg_(1−y)Sb has shown decent thermoelectric performance as well as complex structure transitions,which are closely related to the Ag defects in the anionic l...As novel Zintl phases with the LiGaGe structure type,Ca1−xCexAg_(1−y)Sb 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−δ)Sr_(δ)La_(x)Ag_(1−y)Sb(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_(0.55)Sr_(0.3)La_(0.15)Ag_(0.89)Sb,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.展开更多
基金financial support from the National Natural Science Foundation of China(Grant No.51771105 and 51271098).
文摘As novel Zintl phases with the LiGaGe structure type,Ca1−xCexAg_(1−y)Sb 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−δ)Sr_(δ)La_(x)Ag_(1−y)Sb(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_(0.55)Sr_(0.3)La_(0.15)Ag_(0.89)Sb,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.
