【摘要】 以Ⅱ、Ⅲ和Ⅳ族元素为主的笼状物热电材料研究近年来发展迅速,尤其是在优值系数ZT值上取得了重大突破,而从Sr-Al-Ge笼状物体系中获得的层状结构热电材料却鲜有人关注.本研究利用铝元素作为助溶剂,在1150℃下成功合成了层状SrAl₂Ge₂单晶.采用X射线衍射仪对样品粉末进行表征,通过Rietveld精修证明该晶体具有CaAl₂Si₂结构（空间群为P3-m1,晶胞参数a=b=4.2339（1）?,c=7.4809（0）?）.变温电阻率测试发现单晶样品沿c轴方向具有p型半导体行为,此外其在2～300 K低温下的比热（C_p）数据符合德拜模型.本研究结果对于开发新型无毒、高性能热电材料具有一定参考价值.更多还原

【Abstract】 Ⅱ,Ⅲ and Ⅳ groups were widely investigated to synthesize guest-host thermoelectric compounds in order to obtain high optimal ZT value materials. While a novel layered structure was less reported for Sr-Al-Ge system. In this study, SrAl₂Ge₂ single crystal was grown by aluminum flux at 1150 ℃ and characterized by powder X-ray methods. It is isotropic and crystallize in the CaAl₂Si₂-type structure through the Rietveld refinement method（space group P3-m1） with the lattice constants a=b=4.2339（1）?, c=7.4809（0） ?. Temperature-depended resistivity on single crystals along the c-axis shows p-type semiconducting behavior. Heat capacity（C_p） was measured in 2～300 K and low temperature C_p was consistent with data calculated by using Debye model. This work opens up a novel avenue for seeking and designing environment-friendly and high-performance thermoelectric materials.更多还原