SPECTRAL EVIDENCE OF CONNECTED STRUCTURES IN LIQUID WATER - EFFECTIVERAMAN DENSITY OF VIBRATIONAL-STATES

We present experimental results of the effective Raman density of stat es showing that water both in normal and supercooled states has a frac ton behavior. We have unambiguously determined a crossover frequency o mega(co) between the phonon and fracton regimes. The obtained spectral results and the temperature behavior of omega(co) are consistent with the correlated-site percolation model indicating the existence of fou r-bonded patches whose spatial extent increases with decreasing temper ature. This picture for the water system is confirmed from the spectra l results of two different water-alcohol mixtures; the first one with ethanol, which acts as a ''patch-breaking'' impurity, and the second o ne with butoxyethanol, which can be considered as a ''patch-increasing '' impurity.