Synthesis of technetium hydride TcH${}_{1.3}$ at 27 GPa

Abstract

In this work, we synthesize and investigate lower technetium hydrides at pressures up to 45 GPa using the synchrotron X-ray diffraction, reflectance spectroscopy, and ab initio calculations. In the Tc-H system, the hydrogen content in TcH${}_x$ phases increases when the pressure rises, and at 27 GPa we found a new hexagonal (hcp) nonstoichiometric hydride TcH${}_{1.3}$. The formation of technetium hydrides is also confirmed by the emergence of a new reflective band at 450-600 nm in the reflectance spectra of TcH${}_x$ samples synthesized at 45 GPa. On the basis of the theoretical analysis, we proposed crystal structures for the TcH${}_{0.45\pm 0.05}$ (Tc${}_{16}$H${}_7$) and TcH${}_{0.75\pm 0.05}$ (Tc${}_4$H${}_3$) phases previously obtained at 1-2 GPa. The calculations of the electron-phonon interaction show that technetium hydrides TcH${}_{1+x}$ do not possess superconducting properties due to the low electron-phonon interaction parameter ($\lambda \sim 0.23$).

References in corpus (21)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Phonons and related properties of extended systems from density-functional perturbation theory
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Separable Dual Space Gaussian Pseudo-potentials
• Relativistic separable dual-space Gaussian Pseudopotentials from H to Rn
• Conventional superconductivity at 203 K at high pressures
• Superconductivity at 250 K in lanthanum hydride under high pressures
• Evidence for superconductivity above 260 K in lanthanum superhydride at megabar pressures
• Anomalous high-temperature superconductivity in YH${}_6$
• Superconductivity at 161 K in Thorium Hydride $Th{H}_{10}$: Synthesis and Properties
• Superconductivity at 253 K in lanthanum-yttrium ternary hydrides
• High-Temperature Superconductivity in Cerium Superhydrides
• On Distribution of Superconductivity in Metal Hydrides
• Improved tetrahedron method for the Brillouin-zone integration applicable to response functions
• Superconducting Praseodymium Superhydrides
• Spectroscopy of H${}_3$S: evidence of a new energy scale for superconductivity
• High-Pressure Synthesis of Barium Superhydrides: Pseudocubic BaH12
• High-Pressure Synthesis of Magnetic Neodymium Polyhydrides
• Novel Strongly Correlated Europium Superhydrides
• High-temperature superconductivity in hydrides
• Sr-Doped Molecular Hydrogen: Synthesis and Properties of SrH${}_{22}$

Cited by in corpus (1)

• Discovery of superconductivity in technetium-borides at moderate pressures