Peña-Alvarez Miriam, Li Bin, Kelsall Liam C, Binns Jack, Dalladay-Simpson Philip, Hermann Andreas, Howie Ross T, Gregoryanz Eugene
Centre for Science at Extreme Conditions & The School of Physics and Astronomy, The University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, U.K.
National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China.
J Phys Chem Lett. 2020 Aug 6;11(15):6420-6425. doi: 10.1021/acs.jpclett.0c01807. Epub 2020 Jul 27.
The Co-H system has been investigated through high-pressure, high-temperature X-ray diffraction experiments combined with first-principles calculations. On compression of elemental cobalt in a hydrogen medium, we observe face-centered cubic cobalt hydride (CoH) and cobalt dihydride (CoH) above 33 GPa. Laser heating CoH in a hydrogen matrix at 75 GPa to temperatures in excess of ∼800 K produces cobalt trihydride (CoH) which adopts a primitive structure. Density functional theory calculations support the stability of CoH. This phase is predicted to be thermodynamically stable at pressures above 18 GPa and to be a superconductor below 23 K. Theory predicts that this phase remains dynamically stable upon decompression above 11 GPa where it has a maximum of 30 K.
通过高压、高温X射线衍射实验结合第一性原理计算对Co-H体系进行了研究。在氢气介质中对元素钴进行压缩时，我们在33 GPa以上观察到面心立方氢化钴（CoH）和二氢化钴（CoH）。在75 GPa的氢气基质中用激光将CoH加热到超过约800 K的温度会产生具有原始结构的三氢化钴（CoH）。密度泛函理论计算支持CoH的稳定性。预计该相在18 GPa以上的压力下热力学稳定，在23 K以下是超导体。理论预测，该相在11 GPa以上减压时仍保持动态稳定，此时其最高温度为30 K。
