The solubility range of interstitial Ni in the ZrNi1+xSn half-Heusler phase is a controversial issue,but it has an impact on the thermoelectric properties.In this study,two isothermal section phase diagrams of the Zr-...The solubility range of interstitial Ni in the ZrNi1+xSn half-Heusler phase is a controversial issue,but it has an impact on the thermoelectric properties.In this study,two isothermal section phase diagrams of the Zr-Ni-Sn ternary system at 973K and 1173 K were experimentally constructed based on the binary phase diagrams of Zr-Ni,Zr-Sn,and Ni-Sn.The thermodynamic equilibrium phases were obtained after a long time of heating treatment on the raw alloys prepared by levitation melting.Solubilities of x<0:07 at 973 K and x<0:13 at 1173 K were clearly indicated.An intermediate-Heusler phase with a partly filled Ni void was observed,which is believed to be beneficial to the lowered lattice thermal conductivity.The highest ZT value~0:71 at 973 K was obtained for ZrNi_(1.11)Sn_(1.04).The phase boundary mapping provides an important instruction for the further optimization of ZrNiSn-based materials and other systems.展开更多
基金This work was funded by the National Natural Science Foundation of China(51971081,11674078,and 51871081)the National Key Research&Development Program of China(2017YFA0303600)+2 种基金the National Natural Science Foundation of Guangdong Province of China(2018A0303130033)Shenzhen Fundamental Research Projects(JCYJ20170811155832192)Shenzhen Science and Technology Innovation Plan(KQISCX20180328165435202).
文摘The solubility range of interstitial Ni in the ZrNi1+xSn half-Heusler phase is a controversial issue,but it has an impact on the thermoelectric properties.In this study,two isothermal section phase diagrams of the Zr-Ni-Sn ternary system at 973K and 1173 K were experimentally constructed based on the binary phase diagrams of Zr-Ni,Zr-Sn,and Ni-Sn.The thermodynamic equilibrium phases were obtained after a long time of heating treatment on the raw alloys prepared by levitation melting.Solubilities of x<0:07 at 973 K and x<0:13 at 1173 K were clearly indicated.An intermediate-Heusler phase with a partly filled Ni void was observed,which is believed to be beneficial to the lowered lattice thermal conductivity.The highest ZT value~0:71 at 973 K was obtained for ZrNi_(1.11)Sn_(1.04).The phase boundary mapping provides an important instruction for the further optimization of ZrNiSn-based materials and other systems.
