论文标题
关于fe $ _2 $ v $ _ {0.8} $ W $ _ {0.2} $ al薄膜的结构和电子属性
On the structure and electronic properties of Fe$_2$V$_{0.8}$W$_{0.2}$Al thin films
论文作者
论文摘要
最近在380 K时报道了一个非常大的功绩ZT = 6的热电学图，以Fe $ _2 $ v $ _ {0.8} $ w $ _ {0.2} $ al。在此形式下，fe $ _2 $ v $ _ {0.8} $ w $ _ {0.2} $ al实验中以无序的A2晶体结构结晶，与其散装形式结构（L21）不同。因此，此处报告了特殊的准兰多结构（SQS）方法生成的A2-FE $ _2 $ V $ _ {0.8} $ W $ _ {0.8} $ W $ _ {0.8} $ W $ _ {0.8} $ W $ _ {0.8} $ w $ _ {0.8} $ w $ _ {0.8} $ w $ _这些计算明确地表明A2-FE $ _2 $ v $ _ {0.8} $ W $ _ {0.2} $ Al是0 K时的铁磁金属，在400 k时显示一个小的Seebeck系数（<30 microv/k）。本结果与在费米级别发生深层伪差距的情况相矛盾，以前被调用以证明Zt = 6在Fe $ _2 $ _2 $ v $ _ {0.8} $ w $ _ {0.2} $ _ {0.2} $ al薄膜中。
A very large thermoelectric figure of merit ZT = 6 at 380 K has recently been reported in Fe$_2$V$_{0.8}$W$_{0.2}$Al under thin-film form (Hinterleitner et al., Nature 576 (2019) 85). Under this form, Fe$_2$V$_{0.8}$W$_{0.2}$Al experimentally crystallizes in a disordered A2 crystal structure, different from its bulk-form structure (L21). First principles calculations of the electronic structure performed in A2-Fe$_2$V$_{0.8}$W$_{0.2}$Al supercells generated by the Special Quasi-random Structure (SQS) method are thus reported here. These calculations unambiguously indicate that A2-Fe$_2$V$_{0.8}$W$_{0.2}$Al is a ferromagnetic metal at 0 K, displaying a small Seebeck coefficient at 400 K (< 30 microV/K). The present results contradict the scenario of the occurrence of a deep pseudo-gap at the Fermi level, previously invoked to justify ZT = 6 in Fe$_2$V$_{0.8}$W$_{0.2}$Al thin films.
