Superheating water by CW excitation of gold nanodots.

A temperature-dependent photoluminescent thin film of Al(0.94)Ga(0.06)N doped with Er(3+) is used to measure the temperature of lithographically prepared gold nanodots. The gold nanodots and thin film are excited simultaneously with a continuous wave (CW) Nd:YAG 532 nm laser. The gold nanodot is submersed under water, and the dot is subsequently heated. The water immediately surrounding the nanodot is superheated beyond the boiling point up to the spinodal decomposition temperature at 594 ± 17 K. The spinodal decomposition has been confirmed with the observation of critical opalescence. We characterize the laser scattering that occurs in unison with spinodal decomposition due to an increased coherence length associated with the liquid-liquid transition.