Superconducting Zirconium Polyhydrides at Moderate Pressures.


Type
Article
Change log
Authors
Xie, Hui 
Zhang, Wenting 
Duan, Defang 
Huang, Xiaoli 
Huang, Yanping 
Abstract

Highly compressed hydrides have been at the forefront of the search for high-Tc superconductivity. The recent discovery of record-high Tc's in H3S and LaH10±x under high pressure fuels the enthusiasm for finding good superconductors in similar hydride groups. Guided by first-principles structure prediction, we successfully synthesized ZrH3 and Zr4H15 at modest pressures (30-50 GPa) in diamond anvil cells by two different reaction routes: ZrH2 + H2 at room temperature and Zr + H2 at ∼1500 K by laser heating. From the synchrotron X-ray diffraction patterns, ZrH3 is found to have a Pm3̅n structure corresponding to the familiar A15 structure, and Zr4H15 has an I4̅3d structure isostructural to Th4H15. Electrical resistance measurement and the dependence of Tc on the applied magnetic field of the sample showed the emergence of two superconducting transitions at 6.4 and 4.0 K at 40 GPa, which correspond to the two Tc's for ZrH3 and Zr4H15.

Description
Keywords
34 Chemical Sciences, 51 Physical Sciences, 5104 Condensed Matter Physics
Journal Title
Journal of Physical Chemistry Letters
Conference Name
Journal ISSN
1948-7185
1948-7185
Volume Title
Publisher
American Chemical Society
Rights
All rights reserved
Sponsorship
Royal Society (WM150023)
Engineering and Physical Sciences Research Council (EP/P022596/1)
This work was supported by the National Key R&D Program of China (No. 2018YFA0305900), National Natural Science Foundation of China (Nos. 51632002, 11674122, 51572108, and 11504127), Program for Changjiang Scholars and Innovative Research Team in University (No. IRT_15R23), the 111 Project (No. B12011), and the Natural Sciences and Engineering Research Council of Canada (NSERC). C.J.P. acknowledges financial support from the Engineering and Physical Sciences Research Council (Grant EP/P022596/1) and a Royal Society Wolfson Research Merit award.