LOW TEMPERATURE TEM INVESTIGATION OF ELECTRON BEAM INDUCED DECOMPOSITION OF NANOCRYSTALLINE HYDROZINCITE INTO ZnO

The fast decomposition of hydrozincite (Zn5(CO3)2(OH)6) into ZnO observed in the transmission electron microscope could be slowed down and investigated in situ by operating the microscope at very low electron beam current densities and cooling the specimen down to -160 o C. Thus, it was possible to observe and pursue the distinct structural steps of the disruption of the hydrozincite lattice due to the energetic emission of H2O and CO2 gases. The initially formed disordered ZnO phase was found to further crystalize resulting in a mesoporous structure of small ZnO nanocrystals.