High-Temperature Superconductivity in Alkaline and Rare Earth Polyhydrides at High Pressure: A Theoretical Perspective
| Autor: | Zurek, Eva, Bi, Tiange |
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| Rok vydání: | 2018 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1063/1.5079225 |
| Popis: | The theoretical exploration of the phase diagrams of binary hydrides under pressure using \emph{ab initio} crystal structure prediction techniques coupled with first-principles calculations has led to the \emph{in silico} discovery of numerous novel superconducting materials. This Perspective article focuses on the alkaline earth and rare earth polyhydrides whose superconducting critical temperature, $T_c$, was predicted to be above the boiling point of liquid nitrogen. After providing a brief overview of the computational protocol used to predict the structures of stable and metastable hydrides under pressure, we outline the equations that can be employed to estimate $T_c$. The systems with a high $T_c$ can be classified according to the motifs found in their hydrogenic lattices. The highest $T_c$s are found for cages that are reminiscent of clathrates, and the lowest for systems that contain atomic and molecular hydrogen. A wide variety of hydrogenic motifs including 1- and 2-dimensional lattices, as well as H$_{10}^{\delta-}$ molecular units comprised of fused H$_5^{\delta-}$ pentagons are present in phases with intermediate $T_c$s. Some of these phases are predicted to be superconducting at room temperature. Some may have recently been synthesized in diamond anvil cells. Comment: 12 pages, 5 figures, 3 tables, perspective |
| Databáze: | arXiv |
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