Superconductivity at 161 K in thorium hydride ThH10: Synthesis and properties. (March 2020)

• Record Type: Journal Article
• Authors: Semenok, Dmitry V.; Kvashnin, Alexander G.; Ivanova, Anna G.; Svitlyk, Volodymyr; Fominski, Vyacheslav Yu.; Sadakov, Andrey V.; Sobolevskiy, Oleg A.; Pudalov, Vladimir M.; Troyan, Ivan A.; Oganov, Artem R.
• Is Part Of: Materials today. Volume 33(2020)
• Page Start: 36
• Page End: 44
• Publication Date: 2020-03
• Subjects: Thorium hydrides -- USPEX -- High pressure -- Superconductivity -- X-ray diffraction; Materials science -- Periodicals; Metallurgy -- Periodicals; Metal-work -- Periodicals; Biomedical and Dental Materials -- Periodicals; Manufactured Materials -- Periodicals; Metals -- Periodicals; 620.11
• DOI: 10.1016/j.mattod.2019.10.005
• Languages: English
• ISSNs: 1369-7021

Abstract

Graphical abstract: Abstract: Here we report targeted high-pressure synthesis of two novel high- TC hydride superconductors, P 63 /mmc- ThH9 and F m 3 - m -ThH10, with the experimental critical temperatures ( TC ) of 146 K and 159–161 K and upper critical magnetic fields ( μHC ) 38 and 45 Tesla at pressures 170–175 Gigapascals, respectively. Superconductivity was evidenced by the observation of zero resistance and a decrease of TC under external magnetic field up to 16 Tesla. This is one of the highest critical temperatures that has been achieved experimentally in any compound, along with such materials as LaH10, H3 S and HgBa2 Ca x Cu2 O6+ z . Our experiments show that fcc -ThH10 has stabilization pressure of 85 GPa, making this material unique among all known high- TC metal polyhydrides. Two recently predicted Th-H compounds, I4/mmm -ThH4 (>86 GPa) and Cmc 21 - ThH6 (86–104 GPa), were also synthesized. Equations of state of obtained thorium polyhydrides were measured and found to be in excellent agreement with the theoretical calculations. New phases were examined theoretically and their electronic, phonon, and superconducting properties were calculated.