论文标题
新颖相关的Europium Superhydrides
Novel Strongly Correlated Europium Superhydrides
论文作者
论文摘要
我们在86-130 GPA的压力下对欧洲多水的高压化学进行了联合实验理论研究。我们发现了几种通过Anharmonic效果稳定的新型磁性EU Super Hydries：Cutic $ EUH_ {9} $，Hexagonal $ EUH_ {9} $，以及意外的Cutic（PM-3N）杂质阶段，$ EU_ {8} H_ {46} $。 Monte Carlo simulations indicate that cubic $EuH_{9}$ has antiferromagnetic ordering with T(Neel) up to 24 K, whereas hexagonal $EuH_{9}$ and Pm-3n-$Eu_{8}H_{46}$ possess ferromagnetic ordering with T(Curie) = 137 and 336 K, respectively.在所有研究的Europium Hydride中，电子 - 音波相互作用都较弱，并且它们的磁性排序排除了S波超导性，除了扭曲的pseudohexagonal $ euh_ {9} $外，也许除外。在DFT+U方法中预测的状态方程（在线性响应理论中发现了Hubbard校正）与实验数据密切一致。这项工作表明了原子半径对超水晶结构及其热力学稳定性的晶体结构的对称性畸变的巨大影响。
We conducted a joint experimental-theoretical investigation of the high-pressure chemistry of europium polyhydrides at pressures of 86-130 GPa. We discovered several novel magnetic Eu superhydrides stabilized by anharmonic effects: cubic $EuH_{9}$, hexagonal $EuH_{9}$, and an unexpected cubic (Pm-3n) clathrate phase, $Eu_{8}H_{46}$. Monte Carlo simulations indicate that cubic $EuH_{9}$ has antiferromagnetic ordering with T(Neel) up to 24 K, whereas hexagonal $EuH_{9}$ and Pm-3n-$Eu_{8}H_{46}$ possess ferromagnetic ordering with T(Curie) = 137 and 336 K, respectively. The electron-phonon interaction is weak in all studied europium hydrides, and their magnetic ordering excludes s-wave superconductivity, except, perhaps, for distorted pseudohexagonal $EuH_{9}$. The equations of state predicted within the DFT+U approach (the Hubbard corrections were found within linear response theory) are in close agreement with the experimental data. This work shows the great influence of the atomic radius on symmetry-breaking distortions of the crystal structures of superhydrides and on their thermodynamic stability.
