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

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.