Fast vapor phase growth of SiO2 nanowires via surface-flow on Ag
core/SiO2 shell structure
Lei Gao1, Ailing Ji1, Nianpeng Lu1, Chaorong Li2 and Zexian Cao1*
1
Institute of Physics, Chinese Academy of Sciences, P. O. Box 603, Beijing 100190, China
2Department
of Physics, Zhejiang Sci-Tech. University, Hangzhou 310018, China.
E-mail: zxcao@iphy.ac.cn
Supplemental material contents
Figure S1:
Correlation between the temperatures measured beneath the
crucible and at the top of the substrate.
Figures S2 and S3: SiO2 nanowires grown under various conditions.
*
Figure S4:
Frozen Ag spherules sitting on SiO2 petals.
Figure S5:
SiO2 nanowires embedding pierced Ag particles.
Figure S6:
Catalysis of two SiO2 nanowires by one Ag particle.
To whom correspondence should be addressed. E-mail: zxcao@iphy.ac.cn
1
Figure S1. Correlation between the temperature measured at the heat source beneath the
crucible and that measured at the top of the substrate. This curve is helpful for the
estimation of the temperature at the region concerned.
Figure S2. SEM micrograph showing a part of substrate covered by interweaving SiO2
nanowires. Evaporation temperature: (1200℃).
2
Figure S3.
In the region at the top of a substrate where it is relatively a little colder,
aggregations of SiO2 particles, Ag crystals of micrometer size are visible through the
thicket of nanowires. Evaporation temperature: 1100℃.
Figure S4. SEM micrograph showing core/shell structures with the SiO2 shell just fully
peeled off from the Ag core, resulting in Ag spherules sitting on a SiO2 pedestal. Some
Ag spherules were removed, leaving behind the empty SiO2 pedestals.
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Figure S5. SiO2 nanowires showing a chain of embedded Ag particles, resulting from
the tearing of the catalytic Ag droplet in the case of abundant SiO2 molecules supply.
Evaporation temperature: 1200℃.
Figure S6. A Ag particle simultaneously catalyzing two nanowires of SiO2. This occurs
when the primary liquid Ag core/ SiO2 shell structure comes into contact with the
substrate at two points.
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