Single Crystal X-Ray Diffraction Investigation of High Tc K/Rb/Cs-B-H Mixtures

Recent computational predictions suggest that alkali borohydrides, notably KB2H8, RbB2H8, and CsB2H8, could exhibit high-temperature superconductivity at significantly lower pressures than known binary hydrides. These ternary hydrides are predicted to have superconducting transition temperatures (Tc) up to 146 K at ~12 GPa, making them highly promising candidates for experimental studies. Their broad chemical phase space and complex, likely heterogeneous nature resulting from laser-heating requires SCXRD for unambiguous structure determination.This study will investigate the formation and stability of K-, Rb-, and Cs-B-H phases in laser-heated diamond anvil cells (LHDACs) up to 45 GPa, employing SCXRD on the ID15B beamline to determine the unit cell, space group, and atomic positions (excluding H atoms) of the synthesized compounds. This study will shed light on their phase diagrams, structures, and superconducting properties, aiding the search for high-Tc materials at lower pressures.