Remarkable nanoscopic changes were observed in-situ in metastable oxid
e particles on the room temperature stage of a TEM under an electron b
eam intensity of 10(19)e/cm(2)sec. Particles of 10-15 nm diameter alph
a-Al2O3 and 5nm diameter Al metal were obtained from 100nm metastable
theta-Al2O3 particles by a process dependent on the electron beam inte
nsity. Al nanoparticles were bonded by continuous irradiation via surf
ace diffusion of Al atom and the formation of 2 nm sized Al clusters.
The effects of the electron beam are the irradiation induced increase
of the oxygen mobility and localized heating.