Atomic-Scale Dynamic Observation Reveals Temperature ...Supplementary Figure 5. Image and line...
Transcript of Atomic-Scale Dynamic Observation Reveals Temperature ...Supplementary Figure 5. Image and line...
Supplementary Information
Atomic-Scale Dynamic Observation Reveals
Temperature-Dependent Multistep Nucleation
Pathways in Crystallization
Junjie Lia,b
*, Yunping Lic, Qiang Li
d, Zhongchang Wang
e, Francis Leonard Deepak
a*
a Nanostructured Materials Group, Department of Advanced Electron Microscopy, Imaging and
Spectroscopy, International Iberian Nanotechnology Laboratory (INL), Avenida Mestre Jose
Veiga, Braga 4715-330, Portugal
b CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang
Technical Institute of Physics & Chemistry, CAS; Xinjiang Key Laboratory of Electronic
Information Materials and Devices, 40-1 South Beijing Road, Urumqi 830011, China.
c State Key Lab for Powder Metallurgy, Central South University, Changsha 410083, China
d School of Mechanical Engineering, University of Shanghai for Science and Technology,
Shanghai 200093, China
e Department of Quantum and Energy Materials, International Iberian Nanotechnology
Laboratory (INL), Avenida Mestre Jose Veiga, 4715-330 Braga, Portugal
Email: [email protected] and [email protected]
Electronic Supplementary Material (ESI) for Nanoscale Horizons.This journal is © The Royal Society of Chemistry 2019
Experimental Section
Sample preparation and characterization: A molten salt route was used to prepare the
SrBi2Ta2O9 (SBTO) nanoplatelets1. In a typical synthesis process, the stoichiometric strontium
nitrate (Sr(NO3)2, 99.5%), bismuth oxide (Bi2O3, 99.9%) and tantalum oxide (Ta2O5, 99.9%)
were used as starting materials. 1.1g starting materials were mixed with 1.240 g potassium
chloride (KCl, 99.9%) and 0.974 g sodium chloride (NaCl, 99.9%) in an agate mortar for 0.5 h.
The mixtures were loaded into an alumina crucible and heated at 850oC for 3 h in air, followed
by natural cooling to room temperature in a tube furnace. The resultant white samples were
washed with deionized water three times to remove the KCl and NaCl solvent, and dried at 60°C
for 2 h in an oven. The chemical composition of the obtained products was identified by powder
X-ray diffraction (XRD) (X’Pert PRO diffractometer, PANalytical).
In-situ TEM/STEM observation and EDS analysis: The obtained SBTO samples were dispersed
in ethanol by ultrasonication for 1 h, and a drop of the white suspension was transferred onto
carbon support or heating device. TEM/STEM imaging and EDS mapping were carried out on
the Titan Themis TEM equipped with both probe and image Cs corrector and super-X EDS
detector at 200 kV, which offered an unprecedented opportunity to probe ultra-small structures
with sub-Ångström resolution. The heating experiments were carried out in the TEM using a
disposable, micro-electromechanical system (MEMS) device which serves as both support grid
for the sample and the heating element by connecting the heating stage to an external power
supply2,3
. The Videos were recorded using Tecnai Imaging and Analysis (TIA) software.
The calculations of electron beam induced temperature rise at different electron doses in
TEM.
The electron dose induced maximum temperature rise based on the Bethe theory and Fisher’s
model4,5
,
Δ T =𝐼 𝛥 𝐸 𝑎2
4 𝑘 𝑑 (1 + 2 ln
b
𝑎)
where Δ T represents the temperature rise induced by electron beam, I is the beam dose, ĸ is
thermal conductivity, Δ E is energy loss of per electron, d is the thickness of sample, b and a
represent the radius of conductor and beam radius, respectively. In the thin sample, the electron
energy loss is small even for electrons ~200 keV6. Here, the energy loss per electron is
considered as 6.41×10-16 J, ĸ =1.0 W/K/m7-8
, d = 20 nm, b = 300 nm. For the electron dose of
25000 e/A2S in Figure 1, the temperature rise Δ T is about 208 K, 187 K and 41 K for Figure 2
and 3. The room temperature is kept at 20 oC. Therefore, the calculated temperatures (T = Δ T +
Trm) of the Bi nanoparticles in Figure 1 to 3 heated by electron beam are about 228 oC, 207
oC,
and 61 oC , respectively.
References
1. Y. Li, et al. Chem. Mater. 2013, 25, 2045-2050.
2. J. Li, Z. Wang, F. L. Deepak, J. Phys. Chem. Lett. 2018, 9, 961-969.
3. M. A. Asoro, D. Kovar, P. J. Ferreira, ACS nano 2013, 7, 7844-7852.
4. H.A. Bethe, Handbuch der Physik. vol. 4, 273, Julius Springer (Berilin) (1933).
5. Fisher, S. On the temperature rise in electron irradiated foils. Radiat. Eff. 5, 239-243 (1970).
6. Kim, G.-S. et al. Reduction in thermal conductivity of Bi thin films with high-density ordered
nanoscopic pores. Nanoscale Res. Lett. 8, 371 (2013).
7. Song, D. et al. Thermal conductivity of nanoporous bismuth thin films. Appl. Phys. Lett. 84,
1883-1885 (2004).
8. Tachibana, M. Thermal conductivity of Aurivillius compounds Bi2WO6, SrBi2Ta2O9, and
Bi4Ti3O12. Solid State Commun. 211, 1-3 (2015).
Supplementary Figure 1. XRD analysis. XRD results for the obtained powder samples
revealing the successful preparation of pure SrBi2Ta2O9 with an orthorhombic structure (JCPDS
card no. 05-0519).
10 20 30 40 50 60 70 80 90 100 110 120
(4
2 1
4)
(3
3 1
7)
(0
0 1
0)
(4
3 7
)
(3
4 0
)
(3
1 1
5)
2 (degree)
(4
2 2
)
(1
1 9
)
(3
3 5
) (
3 1
13
)
(4
0 2
)
(2
0 8
)
(1
1 3
)
(1
1 1
3)
(3
2 0
) (2
2 0
)
(0
0 1
0)
(2
0 1
0)
(3
1 5
)
(2
00
) (
1 1
5)
Inte
nsi
ty (
a.u
.)
Supplementary Figure 2. Morphology of the sample. a,c, Low magnification TEM (a) and
HAADF-STEM (b) images for the obtained SrBi2Ta2O9 product. b,d, High resolution TEM and
HAADF-STEM images confirming the orthorhombic structure of the SrBi2Ta2O9. Inset image in
Figure b is the diffraction pattern, confirming the single crystal structure.
a b
c d
SBTO
SBTO
Supplementary Figure 3. Chemical mapping of Bi nanocrystal on SBTO surface. a,
HAADF- STEM image. b–e, Corresponding energy-dispersive x-ray spectroscopy mapping of
Bi (b), Sr (c), Ta (d), and O (e). f, Corresponding EDS spectrum of the Bi nanocrystal taken in
the area marked by an orange square in a.
0 10 20 30 40
Co
un
ts (
a.u
.)
Energy (kev)
a b c
d e f
HAADF-STEM Bi Sr
Ta O
Bi
Bi Bi
Bi
Cu
Cu
Supplementary Figure 4. Morphology of the segregated Bi nanocrystals. High resolution
TEM image showing the formation of the Bi nanocrystals under electron beam irradiation.
Bi nanocrystal
SBTO
Supplementary Figure 5. Image and line profile for a Bi liquid droplet on SrBi2Ta2O9. a, A
typical HRTEM image of a Bi droplet on surface of SrBi2Ta2O9. b, Line profile showing image
intensity along the arrow in (a), illustrating local ordering.
0 10 20 30 40 50 60120
130
140
150
160
170
180
190
No
rmal
ize
d In
ten
sity
Position perpendicular to interface (nm)
b a
Interface ordering
Interface ordering
Bi droplet
SBTO
Liquid
Interface ordering
Surface ordering
Supplementary Figure 6. Size-dependent melting point of Bi nanocrystal based on the in-
situ heating experiment. Error bar is 1nm in Figure S9a, and the scale bar is 10 nm in Figure
S9b-k.
Supplementary Figure 7. Schematic of the electron beam induced Bi nanocrystal growth
under different electron dose.
Supplementary Figure 8. Fast Fourier transformation (FFT) analyses. Corresponding FFT
analyses during the surface and interface ordering droplet to crystal nucleus two-step nucleation
pathway (Video S1). The green and orange colors indicate the liquid and crystal phases,
respectively.
40.0 s 40.8 s 41.6 s 42.4 s
44.8 s
43.2 s 44.0 s
45.6 s 46.4 s 47.2 s 48.0 s 48.8 s
49.6 s 50.4 s 51.2 s 52.0 s 52.8 s 53.6 s
56.8 s 54.4 s 55.2 s 56.0 s 57.6 s 58.4 s
60.8 s 59.2 s 60.0 s 61.6 s
Supplementary Figure 9. Fast Fourier transformation (FFT) analyses. Corresponding FFT
analyses during the surface and interface ordered droplet-interior local ordered solid structure-
crystal nucleus three-step nucleation pathway (Video S2). The green, blue and orange colors
indicate the local ordered solid and crystal phases, respectively.
35.2 s 33.6 s 36.8 s 38.4 s 40.0 s 41.6 s
43.2 s 46.4 s 44.8 s 48.0 s 49.6 s 51.2 s
52.8 s 57.6 s 54.4 s 56.0 s 60.8 s 59.2 s
68.8 s 67.2 s 65.6 s 64.0 s 62.4 s
Supplementary Figure 10. Fast Fourier transformation (FFT) analyses. Corresponding FFT
analyses during the local ordered cluster structure to crystal nucleus two-step nucleation pathway
(Video S3). The blue and orange colors indicate the local ordered cluster and crystal phases,
respectively.
44.0 s 45.6 s 47.2 s 48.8 s 50.4 s
52.0 s 55.2 s 53.6 s 56.8 s 60.0 s 58.4 s
42.4 s
64.8 s 63.2 s 66.4 s 68.0 s 69.6 s
72.8 s 74.4 s 71.2 s
61.6 s
Supplementary Figure 11. Statistical analyses of nucleation dynamics during the multistep
nucleation pathways. a-c, Statistical analyses of the height as a function of time (Video S1, S2
and S3). The green, blue and red lines in d-f represent liquid, local ordered solid and crystal
phase, respectively.
10 20 30 40 50 600
3
6
9
12
Heig
ht
(nm
)
Time (s)0 20 40 60 80 100
0
3
6
9
He
igh
t (n
m)
Time (s)40 50 60 70
0
3
6
9
Heig
ht
(nm
)
Time (s)
a b c
Video Information
Video S1. Two-step nucleation pathway (surface and interface ordered liquid droplet to crystal
nucleus). The Video plays at 2 times the normal speed. The electron dose rate is ~2.5 ×104 e/Å
2s.
Video S2. Three-step nucleation pathway (surface and interface ordered liquid droplet to interior
ordered structure to crystal nucleus). The Video plays at 2 times the normal speed. The electron
dose rate is ~1.8 ×104 e/Å
2s.
Video S3. Two-step nucleation pathway (local ordered cluster structure to crystal nucleus). The
Video plays at 2 times the normal speed. The electron dose rate is ~5.0 ×103 e/Å
2s.