Elastic properties of water under negative pressures

Using Brillouin scattering we have investigated the elastic properties of water under negative pressures. The samples were H2O liquid–vapor inclusions in α-quartz which could be heated to their homogenization temperatures (in the range 120–370 °C); on cooling, negative pressures as high as 1000 bars were reached before a vapor bubble nucleated. The velocity of sound results obtained from our Brillouin experiments indicate that nucleation occurs long before reaching the mechanical instability region where the bulk modulus is zero.