  Understanding the interaction between two bodies in a liquid metal is
important for developing metals with high stiffness, strength, plasticity, and
thermal stability. We conducted atomic force microscopy measurements in liquid
Ga and performed a theoretical calculation in which the statistical mechanics
of a simple liquid containing a quantum effect was used. The experiment and
theory showed unusual behaviours in the interactions between the probe and
substrate in the liquid metal. In the interactions, there were relatively
numerous oscillations and large amplitudes. Furthermore, the interaction ranges
were relatively long. From the theoretical calculations, we found an asymmetric
property that when the probe is solvophilic and the substrate is solvophobic,
the interaction tends to be repulsive; when the solvation affinities are
exchanged, the interaction tends to be attractive in the close position. Our
findings will be useful for understanding and controlling dispersion
stabilities of nanoparticles and chemical reactions in liquid metals.
