Study for material analogs of FeSb2 : Material design for thermoelectric materials
Study for material analogs of FeSb2 : Material design for thermoelectric materials
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DOI：
10.1103/physrevmaterials.2.034604
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发表时间：
2018-03
影响因子：
3.4
通讯作者：
Chang‐Jong Kang;G. Kotliar
中科院分区：
文献类型：
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作者：
Chang‐Jong Kang;G. Kotliar
利用进化算法(在USPEX中实现)和电子结构计算，我们研究了一种新的热电材料FeSbAs的性质，它是一种神秘的热电材料FeSb$2}$的类似物。我们利用密度泛函理论和古兹威尔方法对能量学进行了检验。我们发现FeSbAs可以使热力学稳定在30 Gpa以上。用密度泛函理论研究了FeSbAs的电子结构和热电性质，并与FeSb进行了比较。在50K以上，FeSbAs的Seebeck系数比FeSb高。掺杂后，FeSbAs的优值系数比FeSb更大。另一种类似FeSbP的材料也被研究，发现即使在很高的压力下也是热力学不稳定的。考虑到FeSb${2}$是化合物家族(FeSb${2}$，FeSbAs和FeSbP)的成员，我们阐明了是什么化学处理控制了这一系列中的缺口。我们还研究了Sb在FeSb中的溶解度(As或P)，我们发现Sb的溶解度更高。最后，我们研究了热电性质的双能带模型，发现与温度相关的化学势和电离杂质的存在对于解释FeSb$2}实验中的Seebeck系数的极值是重要的。
Using the \emph{ab initio} evolutionary algorithm (implemented in USPEX) and electronic structure calculations we investigate the properties of a new thermoelectric material FeSbAs, which is a material analog of the enigmatic thermoelectric FeSb$_{2}$. We utilize the density functional theory and the Gutzwiller method to check the energetics. We find that FeSbAs can be made thermodynamically stable above $\sim$30 GPa. We investigate the electronic structure and thermoelectric properties of FeSbAs based on the density functional theory and compare with those of FeSb$_{2}$. Above 50 K, FeSbAs has higher Seebeck coefficients than FeSb$_{2}$. Upon doping, the figure of merit becomes larger for FeSbAs than for FeSb$_{2}$. Another material analog FeSbP, was also investigated, and found thermodynamically unstable even at very high pressure. Regarding FeSb$_{2}$ as a member of a family of compounds (FeSb$_{2}$, FeSbAs, and FeSbP) we elucidate what are the chemical handles that control the gaps in this series. We also investigate solubility (As or P for Sb in FeSb$_{2}$) we found As to be more soluble. Finally, we study a two-band model for thermoelectric properties and find that the temperature dependent chemical potential and the presence of the ionized impurities are important to explain the extremum in the Seebeck coefficient exhibited in experiments for FeSb$_{2}$.