Dynamic behavior of SiO- and SiO_2-coated ZnO ultrafine particles and growth mechanism of Zn_2SiO_4 crystal

摘要

In order to elucidate the stability of a silicon oxide layer on ZnO, the dynamic behavior of SiO- and SiO_2-layer-coated ZnO ultrafine particle surfaces were directly observed by heating in a transmission electron microscope up to 700℃. In the case of SiO-coated ZnO ultrafine particles, ZnO nanocrystallites with the size of 2 nm grew in the SiO layer at 500℃. In the case of SiO_2-coated ZnO ultrafine particles, β-cristobalite with the size of 10 nm order was grown at 600℃. Zn_2SiO_4 particles were grown by coalescence between β-cristobalite and ZnO at 700℃. By comparing the SiO and SiO_2 layers on ZnO ultrafine particles, it was found that the behaviors of the two silicon oxide layers are clearly different.