  In this article, we will present the first experimental observation of
nanojets formed by heating PbO-coated Pb clusters, which has been predicted
theoretically by M. Moseler and U Landman. During the heating, the hot liquid
ejects through the broken orifice into vacuum, and forms a condensed trail in
the tadpole shape as shown in the TEM micrographs. The temperature-variable
Raman spectra indicates that the nanojet formation is closely related to the
heating temperature and thus essentially to the internal pressure in the coated
clusters. The pressure inside the shell, which rises from the inner core's
melting and its confined volume expansion and then drops after the final
explosion, dominates the whole nanojetting process.
