论文标题
在极压处的硼苯胺钙的相图和超导性
Phase Diagram and Superconductivity of Calcium Borohyrides at Extreme Pressures
论文作者
论文摘要
通过使用AB-Initio进化晶体结构预测和密度功能性触发理论，我们从最新的高压超级氢气中发现了近室温度超导性的近室温度超导性，我们从第一原理进行了研究。我们发现，低于100 GPA的所有稳定且弱亚稳态的阶段都在绝缘。这种压力标志着在稳定性的船体上的几个新化学验证阶段的外观，以及CABH $ _5 $中的第一次金属化发作。然后，在不同组合物下，在较高压力下逐渐实现金属化。在Megabar政权中稳定的金属阶段中，我们预测两个高$ T_C $超导阶段，带CABH $ _6 $和Ca $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ _ {13} $组成，重量为119和89 k，分别为300 GPa，分别为300 GPA，分别为低压力。在未来几年中，三元氢化物最有可能在超导研究中发挥重要作用。我们的研究表明，为了减少金属性和超导性的发作压力，对三元氢化物的进一步探索应集中在比硼少的元素上。
Motivated by the recent discovery of near-room temperature superconductivity in high-pressure superhydrides, we investigate from first-principles the high-pressure superconducting phase diagram of the ternary Ca-B-H system, using ab-initio evolutionary crystal structure prediction, and Density Functional Perturbation Theory. We find that below 100 GPa all stable and weakly metastable phases are insulating. This pressure marks the appearance of several new chemically-forbidden phases on the hull of stability, and the first onset of metalization in CaBH$_5$. Metallization is then gradually achieved at higher pressure at different compositions. Among the metallic phases stable in the Megabar regime, we predict two high-$T_c$ superconducting phases with CaBH$_6$ and Ca$_2$B$_2$H$_{13}$ compositions, with critical temperatures of 119 and 89 K at 300 GPa, respectively, surviving to lower pressures. Ternary hydrides will most likely play a major role in superconductivity research in the coming years; our study suggests that, in order to reduce the pressure for the onset of metallicity and superconductivity, further explorations of ternary hydrides should focus on elements less electronegative than boron.
