Order–disorder structural transition in a confined fluid

•The analysis of the amorphous/solid to disordered liquid structural phase transitions of an anomalous confined fluid.•The fractal dimension as a quantitative measure to describe structural transitions.•Structural configuration of particles interacting through a two-length scales potential confined by two infinite plates.•The mapping reported show that the fractal dimension increases with the density and with the temperature.

In this paper we analyze the amorphous/solid to disordered liquid structural phase transitions of an anomalous confined fluid in terms of their fractal dimensions. The model studied is composed by particles interaction through a two-length scales potential confined by two infinite plates. This fluid that in the bulk exhibits water-like anomalies under confinement forms layers of particles. We show that the fluid at the contact layer forms at high densities structures and transitions that can be mapped into fractal dimensions. The multi-fractal singularity spectrum is obtained in all these cases and it is used as the order parameter to quantify the structural transitions for each stage on the confined liquid. This mapping shows that the fractal dimension increases with the density and with the temperature.