【#Tech24H】An international research team led by scientists at the University of Vienna has, for the first time, directly observed a peculiar state known as the "hexatic phase," which exists between solid and liquid, while studying two-dimensional crystalline materials that are only a single atom thick. In everyday life, the melting of ice into water is a typical example of the transition from solid to liquid, a process followed by almost all three-dimensional materials. However, when the thickness of a material is reduced to nearly two dimensions, the melting process becomes unusual: an intermediate state, the "hexatic phase," emerges between the solid and liquid phases. This discovery not only deepens scientists' understanding of phase transition processes but also opens up new directions for the study of materials at the atomic scale.