High-pressure study of the low- Z rich superconductor Be22Re

With Tc∼9.6K, Be22Re exhibits one of the highest critical temperatures among Be-rich compounds. We have carried out a series of high-pressure electrical resistivity measurements on this compound to 30 GPa. The data show that the critical temperature Tc is suppressed gradually at a rate of dTc/dP=-0.05K/GPa. Using density functional theory (DFT) calculations of the electronic and phonon density of states (DOS) and the measured critical temperature, we estimate that the rapid increase in lattice stiffening in Be22Re overwhelms a moderate increase in the electron-ion interaction with pressure, resulting in the decrease in Tc. High-pressure x-ray diffraction measurements show that the ambient pressure crystal structure of Be22Re persists to at least 154 GPa.