Superconducting praseodymium superhydrides.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32158937.
- Also identified by DOI 10.1126/sciadv.aax6849 and PMC identifier 7048426.
- Licence recorded as CC BY-NC.
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Abstract
Superhydrides have complex hydrogenic sublattices and are important prototypes for studying metallic hydrogen and high-temperature superconductors. Previous results for LaH<sub>10</sub> suggest that the Pr-H system may be especially worth studying because of the magnetism and valence-band <i>f</i>-electrons in the element Pr. Here, we successfully synthesized praseodymium superhydrides (PrH<sub>9</sub>) in laser-heated diamond anvil cells. Synchrotron x-ray diffraction analysis demonstrated the presence of previously predicted <i>F</i> <math xmlns="http://www.w3.org/1998/Math/MathML"> <mrow> <mrow><mover><mn>4</mn> <mo>¯</mo></mover> </mrow> </mrow> </math> 3<i>m</i>-PrH<sub>9</sub> and unexpected <i>P</i>6<sub>3</sub>/<i>mmc</i>-PrH<sub>9</sub> phases. Experimental studies of electrical resistance in the PrH<sub>9</sub> sample showed the emergence of a possible superconducting transition (<i>T</i> <sub>c</sub>) below 9 K and <i>T</i> <sub>c</sub> dependent on the applied magnetic field. Theoretical calculations indicate that magnetic order and likely superconductivity coexist in a narrow range of pressures in the PrH<sub>9</sub> sample, which may contribute to its low superconducting temperature. Our results highlight the intimate connections between hydrogenic sublattices, density of states, magnetism, and superconductivity in Pr-based superhydrides.