Liquid metal

About: Liquid metal is a research topic. Over the lifetime, 6947 publications have been published within this topic receiving 77785 citations. The topic is also known as: liquid alloy & liquid metal alloy.

Oxygen mass transfer at liquid-metal-vapour interfaces under a low total pressure

Abstract: The problem of oxygen exchange at the interface between a gas and a liquid metal is treated for systems under a “vacuum” (Knudsen regime, pressures lower than 1 Pa), where, due to the large mean free path of gas molecules in a vacuum, transport processes in the gas phase have no influence on the total interphase mass exchange, which is controlled by interface phenomena and by oxygen partition equilibrium inside the liquid. Owing to the double contribution of molecular O2 and volatile oxides to the oxygen flux from the surface, non-equilibrium steady-state conditions can be established, in which no variations in the composition of the two phases occur with time, as the result of opposite oxygen exchanges. The total oxygen and metal evaporation rates are evaluated as a function of the overall thermodynamic driving forces, and an account of the transport kinetics is given by using appropriate coefficients. A steady-state saturation degree s r, is defined which relates the oxygen activity in the liquid metal to the O2 pressure imposed and to the vapour pressures of volatile oxides. When metals able to form volatile oxides are considered, pressures of molecular O2 higher than those defined under equilibrium conditions have to be imposed in the experimental set-up in order to obtain a certain saturation degree, as a consequence of the condensation of the oxide vapours on the reactor walls. Effective oxidation parameters are determined, which define the conditions leading the liquid to a definite steady-state composition under a “vacuum” when it is out of equilibrium. The effective value of the oxygen pressure which corresponds to the complete oxygen saturation of the metal, $$P_{O_{2,} s}^E $$ , is evaluated at different temperatures for the systems Si-O and Al-O. The results are represented as curves of $$P_{O_{2,} s}^E $$ against T, which separate different oxidation regimes; these results agree well with the experimental data found in the literature.

Molecular Dynamics Study of the Structure of a Rapidly Quenched Metal

Abstract: The molecular dynamics method is used to simulate the rapid-quenching process of a simple liquid metal. The model consists of 864 particles with the density-dependent effective pair potential, which can describe the structure of liquid rubidium above the melting point. The rapid-quenching process from just above the melting point of rubidium down to around 4.2 K is simulated by subtracting the kinetic energy of particles intermittently with the quenching rate of 4.5×10 12 Ks -1 . In the final quenched state at 4.5 K both the pair distribution function and the structure factor show a feature of amorphous states, that is, the split second peak. The relative positions and the ratio of the heights of these split subpeaks are very close to those of the quenched argon (the molecular dynamics simulation) and also of amorphous iron (the evaporated film), and the final quenched state can be considered as a typical model of amorphous pure metals.

Surface modification of liquid metal as an effective approach for deformable electronics and energy devices

Abstract: The fields of flexible or stretchable electronics and energy devices, reconfigurable and compliant soft robotics, wearable e-textiles or health-care devices have paid significant attention to the need of deformable conductive electrodes due to its critical role in device performances. Gallium-based liquid metals, such as the eutectic gallium-indium (EGaIn) being an electrically conductive liquid phase at room temperature, have attracted immense interests as a promising candidate for deformable conductor. However, in the case of bulk liquid metal, there are several limitations such as the need of encapsulation, dispersion in a polymer matrix, or accurate patterning. For these reasons, the preparation of liquid metal particles in harnessing the properties in a non-bulk form and surface modification is crucial for the success of incorporating liquid metal into functional devices. Herein, we discuss the current progress in chemical surface modification and interfacial manipulations of liquid metal particles. The physical and chemical properties of the surface modification-assisted liquid metal polymer composite are also reviewed. Lastly, the applications of the surface-modified liquid metal particles such as flexible electrode, soft robotics, energy storage or harvester, thermal conductor, dielectric sensor, and bioelectronics are discussed, and the corresponding perspectives of deformable electronics and energy devices are provided. In particular, we focus on the functionalization method or requirement of liquid metal particles in each application. The challenging issues and outlook on the applications of surface-modified liquid metal particles are also discussed.