Liquid and solid supercooling of molecular oxygen has been observed and studied in well-characterized porous sol-gel glasses. The depression of the solid-solid phase transition temperature was measured as a function of pore size, showing the strong influence of confinement on the solid phases. The liquid freezing-point depression was also measured, and a picosecond optical technique was used to probe the dynamics of the supercooled liquid. The liquid’s geometrical confinement is observed to have an important effect on its properties, leading to behavior unlike that of ordinary bulk fluids.

• Received 10 December 1986

DOI:https://doi.org/10.1103/PhysRevB.35.6779