Abstract This paper reports that the Ge nanocrystals embedded in SiO$_{2}$ matrix are grown on Si(100) and quartz--glass substrates, and the formation mechanism is systematically studied by using fluorescence x-ray absorption fine structure (XAFS). It is found that the formation of Ge nanocrystals strongly depends on the properties of substrate materials. In the as-prepared samples with Ge molar content of 60%, Ge atoms exist in amorphous Ge (about 36%) and GeO$_{2 }$ (about 24%) phases. At the annealing temperature of 1073 K, on the quartz--glass substrate Ge nanocrystals are generated from crystallization of amorphous Ge, rather than from the direct decomposition of GeO$_{2}$ in the as-deposited sample. However, on the Si(100) substrate, the Ge nanocrystals are generated partly from crystallization of amorphous Ge, and partly from GeO$_{2}$ phases through the permutation reaction with Si substrate. Quantitative analysis reveals that about 10% of GeO$_{2}$ in the as-prepared sample are permuted with Si wafer to form Ge nanocrystals.
Received: 14 July 2006
Revised: 02 February 2007
Accepted manuscript online:
PACS:
81.16.-c
(Methods of micro- and nanofabrication and processing)
(Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization)
Fund: Project
supported by the National Natural Science Foundation of China
(Grant Nos 10605024, 10375059 and 10404023) and Youth Foundation
of University of Science and Technology of China (Grant No
KA2310000002).
Cite this article:
Yan Wen-Sheng(闫文盛), Li Zhong-Rui(李忠瑞), Sun Zhi-Hu(孙治湖), Pan Zhi-Yun(潘志云), and Wei Shi-Qiang(韦世强) Formation mechanism of Ge nanocrystals embedded in SiO2 studied by fluorescence x-ray absorption fine structure 2007 Chinese Physics 16 2764
[1]
Phase transition of solid bismuth under high pressure Hai-Yan Chen(陈海燕), Shi-Kai Xiang(向士凯), Xiao-Zhen Yan(颜小珍), Li-Rong Zheng(郑黎荣), Yi Zhang(张毅), Sheng-Gang Liu(刘盛刚), Yan Bi(毕延). Chin. Phys. B, 2016, 25(10): 108103.
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