Nanojet formation by heating PbO coated Pb clusters

Nanojet means that the liquid is forced to pass through the nozzle with the nanosize diameter. we report here that nanojet was formed for the first time in lab by heating the PbO coated Pb clusters. In this experiment, the coated clusters are heated to more than 200 C and it was found that the inner Pb core melted and ran out from the cracked outer shell with a 200-nm-long(as long) trail. The in situ TEM revealed that the process occurred very quickly. the temperature-variable Raman scattering was carried out to characterize the pressure change of the nano core/shell system, in which, the width of the peak corresponding to the Ag mode of PbO was found increasing slowly between 0°C and 160°C, then abruptly rising and continuing with an abrupt drop after 200°C. It demonstrated the pressure-driving nanojet mechanism. The size effect and the multiple jets were also investigated..