Calorimetric observation of the melting of free water nanoparticles at cryogenic temperatures.
We present an experimental study of the thermodynamics of free, size-selected water cluster anions consisting of 48 and 118 molecules. The measured caloric curves of the clusters are bulklike at low temperatures but show a well-defined, particle-size specific transition at 93+/-3 K for (H2O)48- and 118+/-3 K for (H2O)118-. At the transition temperature the heat capacity strongly increases, which marks the onset of melting.
Universität Freiburg, Hermann-Herder-Strasse 3, Freiburg 79104, Germany.
C
C
Hock
M
M
Schmidt
R
R
Kuhnen
C
C
Bartels
L
L
Ma
H
H
Haberland
B
B
van Issendorff