A recipe for an effective selection of promising candidates for high-temperature superconductors among binary hydrides

TL;DR

This study analyzes a large database of binary hydrides to identify physico-chemical indicators, notably the M_X/M_H ratio, that can effectively predict high-temperature superconductivity, thereby optimizing candidate selection.

Contribution

The paper introduces a novel screening parameter, M_X/M_H ratio, derived from statistical analysis of over 580 compounds, to improve the prediction of high-Tc superconductors among binary hydrides.

Findings

M_X/M_H ratio is a key indicator for high Tc.

28% chance to find Tc > 200 K within specific M_X/M_H range.

Lower M_X/M_H ratios correlate with higher Tc.

Abstract

Recent research on compressed binary hydrides have unveiled the potential for achieving superconductivity at near-room-temperature. Nevertheless, the available decision-making procedures standing behind the selection of constituent elements that may potentially exhibit high values of critical temperature ($T_c$) are far from optimal. In other words, a lot of experimental and numerical effort is wasted on exploring unpromising compounds. By conducting a deep study of a database containing over $580$ binary hydride superconductors, we were able to observe some interesting relationships between $T_c$ and selected physico-chemical properties of examined compounds. Among studied parameters, the ratio of the sum of the molecular weight of heavier atoms to the total mass of all hydrogen atoms in the chemical formula of hydride ($M_X/M_H$) was found to be the most valuable indicator that can help to screen for new promising superconductor candidates. This is because the highest $T_c$ requires the lowest $M_X/M_H$ ratio. Statistical analysis indicates a $28\%$ chance of finding $T_c > 200$ K within $0 < M_X/M_H < 15$. It is expected that these findings will not only allow for more efficient use of resources by improving future superconductor candidates selection but also they will accelerate ongoing experimental and numerical research that should bring new exciting discoveries in a much shorter time.