Liquidmetal and Vitreloy are commercial names of a series of amorphous metal alloys developed by a California Institute of Technology research team, now marketed by a firm that the team organized called Liquidmetal Technologies. The alloys contain atoms of significantly different sizes, leading to low free volume (and therefore high viscosity) when melted. The viscosity prevents the atoms moving enough to form an ordered lattice. The material structure also results in low shrinkage during cooling, and resistance to plastic deformation.Cool stuff. Amorphous metal alloys are actually metallic glass.