Pressure-induced superconductivity at 32 K in MoB2

Abstract

Since the discovery of superconductivity in MgB₂ (<i>T</i>_c ∼ 39 K), the search for superconductivity in related materials with similar structures or ingredients has never stopped. Although about 100 binary borides have been explored, only a few of them show superconductivity with relatively low <i>T</i>_c. In this work, we report the discovery of superconductivity up to 32 K, which is the highest <i>T</i>_c in transition-metal borides, in MoB₂ under pressure. The <i>T</i>_c of MoB₂ in the α phase can be well explained by theoretical calculations in the framework of electron-phonon coupling. Furthermore, the coupling between the <i>d</i> electrons of Mo and the out-of-plane Mo-phonon modes are the main driving force of the 32 K superconductivity of MoB₂. Our study sheds light on the exploration of high-<i>T</i>_c superconductors in transition metal borides.