论文标题
局部订购过渡驱动带隙的闭合：热电杂质的示例
Partial Order-Disorder Transition Driving Closure of Band Gap: Example of Thermoelectric Clathrates
论文作者
论文摘要
在寻求有效的热电学时，半导体行为是目标特性。然而，由于电子结构，温度和混乱之间的复杂相互作用，通常很难实现这一目标。我们发现，热电外层BA $ _8 $ al $ _ {16} $ si $ _ {30} $是这种情况，尽管该材料在其地面上表现出带隙，但温度驱动的部分阶订单端订单级过渡导致了其有效的关闭。通过一种新的方法来计算合金的温度依赖有效带结构，可以实现这一发现。我们的方法充分说明了短距离顺序的影响，可以应用于原始细胞中许多原子的复杂合金，而无需依赖有效的培养基近似。
On the quest for efficient thermoelectrics, semiconducting behavior is a targeted property. Yet, this is often difficult to achieve due to the complex interplay between electronic structure, temperature, and disorder. We find this to be the case for the thermoelectric clathrate Ba$_8$Al$_{16}$Si$_{30}$: Although this material exhibits a band gap in its groundstate, a temperature-driven partial order-disorder transition leads to its effective closing. This finding is enabled by a novel approach to calculate the temperature-dependent effective band structure of alloys. Our method fully accounts for the effects of short-range order and can be applied to complex alloys with many atoms in the primitive cell, without relying on effective medium approximations.
