Superconductivity at 17 K in Yttrium Metal under Nearly Hydrostatic Pressures to 89 GPa

TL;DR

This study reports that yttrium metal becomes superconducting at 17 K under nearly hydrostatic pressures up to 89 GPa, with a linear increase in Tc suggesting higher transition temperatures at greater pressures.

Contribution

It demonstrates a significant increase in Tc for yttrium under nearly hydrostatic high pressure, contrasting previous quasihydrostatic results, and reveals a linear Tc-volume relationship.

Findings

Tc reaches 17 K at 89 GPa

Linear Tc dependence on volume ratio V/Vo

Higher Tc likely at pressures above 89 GPa

Abstract

In an experiment in a diamond anvil cell utilizing helium pressure medium, yttrium metal displays a superconducting transition temperature which increases monotonically from Tc ? 3.5 K at 30 GPa to 17 K at 89.3 GPa, one of the highest transition temperatures for any elemental superconductor. The pressure dependence of Tc differs substantially from that observed in previous studies under quasihydrostatic pressure to 30 GPa. Remarkably, the dependence of Tc on relative volume V/Vo is linear over the entire pressure range above 33 GPa, implying that higher values of Tc are likely at higher pressures. For the trivalent metals Sc, Y, La, Lu there appears to be some correlation between Tc and the ratio of the Wigner-Seitz radius to the ion core radius.