Physically vitrifying amorphous single-element metal requires ultrahigh cooling rates, which are still unachievable for most of the closest-packed metals. Here, we report a facile chemical synthetic strategy for single-element amorphous palladium nanoparticles with a purity of 99.35 at.% ± 0.23 at.% from palladium–silicon liquid droplets. In-situ transmission electron microscopy directly detected the solidification of palladium and the separation of silicon. Further hydrogen absorption experiment showed that the amorphous palladium expanded little upon hydrogen uptake, exhibiting a great potential application for hydrogen separation. Our results provide insight into the formation of amorphous metal at nanoscale.

Various strategies for thermoelectric material optimization have been widely studied and used for promoting electrical transport and suppressing thermal transport. As a nontraditional method, pressure has shown great potential, as it has been applied to obtain a high thermoelectric figure of merit, but the microscopic mechanisms involved have yet to be fully explored. In this study, we focus on r-GeTe, a low-temperature phase of GeTe, and investigate the pressure effects on the electronic structure, electrical transport properties and anharmonic lattice dynamics based on density functional theory (DFT), the Boltzmann transport equations (BTEs) and perturbation theory. Electronic relaxation times are obtained based on the electron-phonon interaction and the constant relaxation time approximation. The corresponding electrical transport properties are compared with those obtained from previous experiments. Hydrostatic pressure is shown to increase valley degeneracy, decrease the band effective mass and enhance the electrical transport property. At the same time, the increase in the low-frequency phonon lifetime and phonon group velocity leads to an increase in lattice thermal conductivity under pressure. This study provides insight into r-GeTe under hydrostatic pressure and paves the way for a high-pressure strategy to optimize transport properties.