Habit and structure of Cd(S, Se) quantum dots in silicate glasses: High-resolution transmission electron microscopy
作者:
Mireille Allais,
Madeleine Gandais,
期刊:
Philosophical Magazine Letters
(Taylor Available online 1992)
卷期:
Volume 65,
issue 5
页码: 243-248
ISSN:0950-0839
年代: 1992
DOI:10.1080/09500839208207542
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
Cd(S, Se) nanocrystals were developed in silicate glass by heat treatments and were characterized by high-resolution transmission electron microscopy. They are crystallized in the hexagonal structure of wurtzite type. Their average size increases with increasing heat-treatment time from 5 to 13 nm at 700°C and from 5 to 10 nm at 675°C. The crystal morphology depends on the size. Below a critical size sc, the shape is close to either a sphere or a hexagonal prism with nearly equivalent dimensions in every direction. Above sc, the crystallites definitely adopt a prismatic habit, growing longer in the direction of the c axis. The critical size depends on the temperature of the heat treatment: At 700°C,scis about 10nm and, at 675°C, it is around 6–7 nm. The basal faces of the prism present an asymmetry, indicating different growth rates in opposite directions of the c axis, in relation to the polarity of the wurtzite structure.
点击下载:
PDF (932KB)
返 回