Advances in theoretical calculations boosted the searches for high temperature superconductors, such as sulfur hydrides and rare-earth polyhydrides. However, the required extremely high pressures for stabilizing these superconductors handicapped further implementations. Based upon thorough structural searches, we identified series of unprecedented superconducting technetium-borides at moderate pressures, including TcB (P63/mmc) with superconducting transition temperature Tc = 20.2 K at ambient pressure and TcB2 (P6/mmm) with Tc = 23.1 K at 20 GPa. Superconductivity in these technetium-borides mainly originates from the coupling between the low frequency vibrations of technetium-atoms and the dominant technetium-4d electrons at the Fermi level. Our works therefore present a fresh group in the family of superconducting borides, whose diversified crystal structures suggest rich possibilities in discovery of other superconducting transition-metal-borides.
@article{arxiv.2403.15283,
title = {Discovery of superconductivity in technetium-borides at moderate pressures},
author = {Xiangru Tao and Aiqin Yang and Yundi Quan and Biao Wan and Shuxiang Yang and Peng Zhang},
journal= {arXiv preprint arXiv:2403.15283},
year = {2024}
}