论文标题
第一原理的磁卤化双钙质CS2（AG，NA）FECL6的电子结构
Electronic structure of the magnetic halide double perovskites Cs2(Ag,Na)FeCl6 from first-principles
论文作者
论文摘要
一个磁卤化双重钙壶（HDP）家族最近引起了人们的关注，因为它们有可能将卤化物双钙钛矿的应用领域扩展到例如。 Spintronics。最新的这些系统的理论建模依赖于密度功能理论（DFT）的原始近似值。在本文中，我们研究了Fe $^{3+} $的结构，电子和磁性 - 包含HDPS CS $ _2 $ _2 $ agfecl $ _6 $和CS $ _2 $ nafecl $ _6 $，使用更先进的基于DFT的方法组合，包括DFT+U，Hybrid-DFT和各种磁性状态。我们研究了在DFT+U和混合参数（$α$，$α$）中更改有效的Hubbard参数u $ _ {eff} $的效果。我们的结果揭示了一组对这些参数高度敏感的局部FE（D）状态。 CS $ _2 $ agfecl $ _6 $和CS $ _2 $ nafecl $ _6 $都是反铁磁体，其温度远低于室温，因此在与大多数应用相关的外部条件下处于敏锐的（PM）状态。因此，我们已经检查了磁性无序对这些系统电子结构的影响，发现虽然CS $ _2 $ nafecl $ _6 $在很大程度上不受影响，但CS $ _2 $ _2 $ agfecl $ _6 $显示出对其电子带结构的重大重归于。
A family of magnetic halide double perovskites (HDPs) have recently attracted attention due to their potential to broaden application areas of halide double perovskites into e.g. spintronics. Up to date the theoretical modelling of these systems have relied on primitive approximations to the density functional theory (DFT). In this paper, we study structural, electronic and magnetic properties of the Fe$^{3+}$-containing HDPs Cs$_2$AgFeCl$_6$ and Cs$_2$NaFeCl$_6$ using a combination of more advanced DFT-based methods, including DFT+U, hybrid-DFT and treatments of various magnetic states. We examine the effect of varying the effective Hubbard parameter, U$_{eff}$, in DFT+U and the mixing-parameter, $α$, in hybrid DFT on the electronic structure and structural properties. Our results reveal a set of localized Fe(d) states that are highly sensitive to these parameters. Cs$_2$AgFeCl$_6$ and Cs$_2$NaFeCl$_6$ are both antiferromagnets with Neél temperatures well below room temperature and are thus in their paramagnetic (PM) state at the external conditions relevant to most applications. Therefore, we have examined the effect of disordered magnetism on the electronic structure of these systems and find that while Cs$_2$NaFeCl$_6$ is largely unaffected, Cs$_2$AgFeCl$_6$ shows significant renormalization of its electronic band structure.
