Influence of nanoconfinement on structure and phase transitions in RbNO3/porous glass composites

This study aims at clarifying the structure, thermal and dielectric properties of a nanocomposite consisting of rubidium nitrate embedded in a porous borosilicate glass matrix (15.3 nm). Experimental data were obtained using X-ray diffraction, Fouriertransform infrared spectroscopy, differential thermal analysis and dielectric measurements, enabling the identification of the effects of nanoconfinement on the phase transitions. It was found that the temperature of phase transition from the trigonal to cubic phase in the filled rubidium nitrate was significantly reduced from 439 K to 422 K. This finding was corroborated by both differential thermal analysis, X-ray diffraction methods and Landau's phenomenological theory