[14a-D62-1~12] 9.2 Nanowires and Nanoparticles

[14a-D62-6] Microsecond time-scale in situ UHVEM observations of crystallization process in amorphous Sb nanoparticles

〇Hidehiro Yasuda¹ (1.Osaka Univ.)

Keywords:nanoparticle, in situ TEM observation

Electron-irradiation-induced crystallization processes of amorphous antimony nanoparticles have been studied by microsecond time-scale in situ observations by UHVEM developed with JEOL Ltd. at Osaka University recently. Amorphous antimony nanoparticles supported on thin amorphous carbon substrates were prepared by vapor-deposition method. Electron irradiation experiments and the simultaneous in situ observations were carried out by JEM-1000EES UHVEM operating at an accelerating voltage of 1 MV, which was equipped with Gatan K2-IS electron direct detection CMOS camera. The time for one frame was 625 microseconds. The figures show a typical example of migration of interface between an amorphous and crystalline phase during crystallization in an approximately 60 nm-sized particle as indicated by arrows. The nucleation site of the crystalline phase is the particle surface. At the early stage of the crystallization the interface has a small curvature, but at the steady state the interface becomes flat. The velocity of interface migration is estimated to be about 10 microsecond/s. The velocity of the interface migration depends on the particle size, and it was confirmed that the smaller the particle size is, the faster the velocity is.