Ultra-large scale syntheses of monodisperse. nanocrystals via a simple and inexpensive route

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1 Supplementary Information for Ultra-large scale syntheses of monodisperse nanocrystals via a simple and inexpensive route JONGNAM PARK 1, KWANGJIN AN 1, YOSUN HWANG 2, JE-GEUN PARK 2, HAN- JIN NOH 3, JAE YOUNG KIM 3, JAE-HOON PARK 3, NONG-MOON HWANG 4, AND TAEGHWAN HYEON *1 Figure S1. FT-IR spectra of the iron-oleate complex. Red curve: the iron-oleate complex. Black curve: the complex after heating at 38 o C. Transmittance (a.u.) -CH 3 -CH 2 -CH 3 C=O Fe-O C=C C-C C-O C=O heat treatment precursor Wavenumber (cm -1 ) 1 24 Nature Publishing Group

2 Figure S2 Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) data of iron-oleate complex. 2 1 Figure images images: 31 É Heat flow (mw) -2 DSC TGA Temperature C) ( S3 T E M (upper low 32 É ( min.) 32 É (1 min.) 32 É (2 min.) 32 É (3 min.) Weight loss (%) 8 ~ 11 nm 12 nm 12 nm 12 nm magnification, bottom images: higher magnification) of the iron oxide nanoparticles taken at various reaction time intervals Nature Publishing Group

3 Figure S4 Particle size distribution histograms of iron oxide nanocrystals. (a) 5 nm, 9 nm, (c) 12 nm, (d) 16 nm and (e) 22 nm. (a) 5 nm relative count diameter (nm) Average diameter = 5.9 nm Size variation = ±.21 nm (± 4.11%) 9 nm Relative count diameter (nm) Average diameter = 9.1 nm Size variation = ±.19 nm (± 2.1%) 3 24 Nature Publishing Group

4 (c) 12 nm Relative count Diameter (nm) Average diameter = nm Size variation = ±.27 nm (± 2.3%) (d) 16 nm Relative count ±âå Diameter (nm) Average diameter = nm Size variation = ±.44 nm (± 2.73%) 4 24 Nature Publishing Group

5 (e) 22 nm Relative count Diameter (nm) Average diameter = 22.6 nm Size variation = ±.79 nm (± 3.57%) 5 24 Nature Publishing Group

6 Figure S5 The size control of monodisperse iron oxide nanocrystals by varying the relative concentration of oleic acid. (a) 9 nm (1.5 mmol); 12 nm (3 mmol); (c) 14 nm (4.5 mmol). (a) (c) 6 24 Nature Publishing Group

7 Figure S6 The power X-ray diffraction (XRD) patterns of (a) 12 nm sized Fe 3 O 4 nanocrystals, 12 nm sized MnO nanocrystals, (c) pencil-shaped CoO nanorods, and (d) 2 nm sized Fe nanocrystals. (a) 12 1 (311) 7 6 (2) Intensity (22) (4) (511) (422) (44) Intensity (111) (22) (311) (222) (c) θ (11) (d) Fe(11) 2θ Intensity (2) (1) (12) (11) (13) (112) Intensity FeO(2) FeO(111) FeO(22) Fe(2) θ θ 7 24 Nature Publishing Group

8 (a) (c) Figure S7 (a) Field dependence of magnetization measured at 5 K after zero-field cooling from 38 K. The inset shows the full hysteresis curve of 16 nm sample measured at 5 K up to 5 Tesla. Size dependence of coercive field, H c, measured at 5 K after zero-field cooling from 38 K. (c) The normalized coercive field (H c /H c ) as function of reduced temperature (T/T B ) for 12 nm sample, where Hc is the coercive field measured at temperature T, H c the estimated coercive field at T=K, and T B the measured blocking temperature from M(T). The solid line is guide for eyes and the dashed line is for a theoretical curve for a single domain of fine particles, (H c /H c ) = 1-(T/T B ) 1/2. (a) 4 M (emu/g) nm 9 nm 12 nm 16 nm 22 nm H (T) H (Oe) M (emu/g) 2 1 (c) 1 8 HC (Oe) Diameter (nm) HC /HC T/T B 8 24 Nature Publishing Group

9 Figure S8 TEM images of (a) 9 nm sized manganese ferrite and 8 nm sized cobalt ferrite nanocrystals. (a) 9 24 Nature Publishing Group

10 (c) Energy dispersive X-ray spectroscopic (EDX) results on the nanoparticles of manganese ferrite and cobalt ferrite. We have conducted energy dispersive X-ray spectroscopic (EDX) studies on the nanoparticles of cobalt ferrite and manganese ferrite. The molar ratio of Co:Fe was 1:1.93, demonstrating that a stoichiometric cobalt ferrite nanoparticles were produced. The molar ratio of Mn:Fe was 1:2.8, showing that iron-rich manganese ferrite was produced. Element Peak Area Area Sigma k factor Abs Corrn. Weight % Weight% Atomic % Mn K Fe K Totals 1. Element Peak Area Area Sigma k factor Abs Corrn. Weight % Weight% Atomic % Fe K Co K Totals Nature Publishing Group

11 Figure S9 TEM images and electron diffraction patterns of the products after reacting iron-oleate complex in octadecene (a) at 26 o C for 1 day, at 26 o C for 3 days, (c) at 24 o C for 3 days, and (d) at 2 o C for 3 days. a) b) c) d) Nature Publishing Group

12 Figure S1. (a) In-situ FT-IR spectra of the iron-oleate complex at various temperatures. Plot of the temperature dependence of the peak intensity of C-H stretching mode (293 cm -1 ) in the IR spectra. (c) In-situ FT-IR spectra of the solution-phase reaction mixture at various temperatures (background spectra from octadecene solvent was subtracted). (a) 25 C 4 C 225 C 375 C Absorbance 2 C 15 C Absorbance 35 C 325 C 1 C 3 C 75 C 275 C 25 C 25 C Wavenumber (cm -1 ) Wavenumber (cm -1 ) Relative Intensity (%) (c) Temperature ( o C) Nature Publishing Group

13 25 É Aging 25 É 24 É 22 É 2 É 1 É 3 É CO 2 C=O Nature Publishing Group