Freezing and melting of Ar in mesopores studied by optical transmission
Ar condensates in a porous Vycor glass with an average pore diameter of 10 nm have been studied by optical transmission. Cooling-heating cycles have been performed through the freezing and melting transition for samples with different fractional fillings. Freezing leads to a decrease of the transmission up to four orders of magnitude due to material transport in the pore network that leads to a coarsening of the pore filling. The results are compared with transmission data on isothermal filling and draining and with heat-capacity data on freezing and melting.