Search for potential high-temperature superconductivity in lanthanum, scandium and magnesium superhydrides at extreme pressures of 250-450 G

Up to date the most promising candidates for ultimate phonon-mediated superconductivity in binary systems are novel crystal structures of a clathrate-type compounds of MH68, MH129 and MH1810 composition (where M is Mg, Sc, La, Ce, Hf, Zr metal) with the developed 3D H-based networks. Among different predicted phases, Fmmm-LaH18 (270 K at 300 GPa), Im-3m-MgH6 (270 K at 350 GPa), Immm-ScH12 (320 K at 300 GPa), Pm-3-MgH12 (375 K at 350 GPa) are stable at pressures, which are achievable in experiment.
The main goal of our project is to synthesize the novel hydrogen-enriched lanthanum, scandium and magnesium hydride phases with promising high Tcs and determine their pressure/temperature stability fields. Recently we regularly achieve pressures above 400 GPa by improving the shape of diamond anvils. This allows us to study YH94 at 400 GPa and gold up to 477 GPa11.