Different from full-Heusler compounds,four vacancies in the face-centered cubic crystal structure provide extra sites for enhancing the thermoelectric properties of half-Heusler compounds(HHs).Herein,excess Ag is intr...Different from full-Heusler compounds,four vacancies in the face-centered cubic crystal structure provide extra sites for enhancing the thermoelectric properties of half-Heusler compounds(HHs).Herein,excess Ag is introduced to the Ni-site vacancies of ZrNiSn to optimize thermoelectric properties.The ZrNiAg_(x)Sn(x=0,0.01,0.02,and 0.03)samples were synthesized by levitation melting and spark plasma sintering.Remarkably,the introduction of excess Ag significantly improves the Seebeck coefficient of ZrNiAg_(0.01)Sn,and a peak power factor of~4.52 mW/(m K^(2))is achieved in ZrNiAg_(0.01)Sn at 923 K,which is enhanced by 22.8%than that of pristine ZrNiSn.As a result,the figure of merit zT of pristine ZrNiSn is enhanced from~0.60 to~0.72 of ZrNiAg_(0.01)Sn at 923 K.Additionally,grain refinement effectively increases the Vickers hardness of ZrNiAg_(0.01)Sn,which is enhanced by 32.8%than that of pristine ZrNiSn.These results demonstrate a viable doping strategy for designing ZrNiSn-based HHs with excellent thermoelectric and mechanical properties.展开更多
In contrary to the commonly used arc melting method, samples in the present paper were prepared by the solid state reaction from elemental powders at 1173 K under a flowing Ar atmosphere for 96-168 h. The constituent ...In contrary to the commonly used arc melting method, samples in the present paper were prepared by the solid state reaction from elemental powders at 1173 K under a flowing Ar atmosphere for 96-168 h. The constituent phases and the elemental compositions were determined and shown that the samples were of single phase and stoichiometry. Then the spark plasma sintering technique was used to consolidate them. It is found that, dense ZrNiSn-based compounds with fine grain size and homogeneous microstructure were achieved under the condition of 1123 K/40 MPa/25 min.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52271025,51927801,and U22A20174)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZC20240173)+1 种基金the Science and Technology Planning Project of Liaoning Province(2023JH2/101700295)the Innovation Foundation of Science and the Technology of Dalian(No.2023JJ12GX021).
文摘Different from full-Heusler compounds,four vacancies in the face-centered cubic crystal structure provide extra sites for enhancing the thermoelectric properties of half-Heusler compounds(HHs).Herein,excess Ag is introduced to the Ni-site vacancies of ZrNiSn to optimize thermoelectric properties.The ZrNiAg_(x)Sn(x=0,0.01,0.02,and 0.03)samples were synthesized by levitation melting and spark plasma sintering.Remarkably,the introduction of excess Ag significantly improves the Seebeck coefficient of ZrNiAg_(0.01)Sn,and a peak power factor of~4.52 mW/(m K^(2))is achieved in ZrNiAg_(0.01)Sn at 923 K,which is enhanced by 22.8%than that of pristine ZrNiSn.As a result,the figure of merit zT of pristine ZrNiSn is enhanced from~0.60 to~0.72 of ZrNiAg_(0.01)Sn at 923 K.Additionally,grain refinement effectively increases the Vickers hardness of ZrNiAg_(0.01)Sn,which is enhanced by 32.8%than that of pristine ZrNiSn.These results demonstrate a viable doping strategy for designing ZrNiSn-based HHs with excellent thermoelectric and mechanical properties.
文摘In contrary to the commonly used arc melting method, samples in the present paper were prepared by the solid state reaction from elemental powders at 1173 K under a flowing Ar atmosphere for 96-168 h. The constituent phases and the elemental compositions were determined and shown that the samples were of single phase and stoichiometry. Then the spark plasma sintering technique was used to consolidate them. It is found that, dense ZrNiSn-based compounds with fine grain size and homogeneous microstructure were achieved under the condition of 1123 K/40 MPa/25 min.
