CVD Growth Mechanism of Single-Walled Carbon Nanotubes from Alcohol

Shigeo Maruyama, Yuhei Miyauchi, Yoichi Murakami,Shohei Chiashi, Erik Einarsson

Department of Mechanical Engineering The University of Tokyohttp://www.photon.t.u-tokyo.ac.jp

NT06 @ Nagano on June 19, 2006

Alcohol CCVD on Catalysts Supported with Zeolite Alcohol CCVD on Catalysts Supported with Zeolite

2.5/2.5 : Fe/Co (wt%) on USY Zeolite 30mg

AlcoholEthanolMethanol

vacuum

Electric FurnaceSimple, High-PurityLow-Temperature

(550-900°C)

S. Maruyama et al., Chem. Phys. Lett. 360 (2002) 229.

As-Grown

500 1000 1500

Inte

nsity

(arb

.uni

ts)

Raman shift (cm–1)

(a) 600°C

(b) 700°C

(c) 800°C

(d) 900°C

(e) Laser–oven

RBM

G band

D band

BWF

7.4[Å]Shinohara& Nagy

Most Used Carbon Source in NT06 synthesis session A

ACCVD Experimental ApparatusACCVD Experimental Apparatus

Ethanol tank

Hot bath

Pressure gauge

Mai

n dr

ain

tube

Sub

drai

n tu

be

Quartz tube

Electric furnace

Pressure gaug

Vacuum pump

Quartz boat

Ar/H2

Aror Ethanol tank

Hot bath

Ethanol tank

Hot bath

Pressure gauge

Mai

n dr

ain

tube

Sub

drai

n tu

be

Quartz tube

Electric furnace

Pressure gaugPressure gaug

Vacuum pumpVacuum pump

Quartz boat

Ar/H2

Aror

ACCVD is Simple!!ACCVD is Simple!!High School Students Presented

at Fullerene-Nanotubes General Symposium @ Univ. of Tokyo, July 28, 2004Synthesis of Single-walled Carbon Nanotubes

from Alcohol by CCVD Method○Miki Kanao, Kieko Sawaguchi and Masaru Moriyasu

東京工業大学工学部附属工業高等学校

0 500 1000 1500

100 200 300 400

2 1 0.9 0.8 0.7

Raman Shift (cm –1 )

Inte

nsity

(arb

. uni

ts)

Diameter (nm)

Large Scale ACCVD Production by TorayLarge Scale ACCVD Production by Toray

TEM Image

High purity SWNTs from Ethanol on Zeolite

Toray Industries, Inc. [東レ株式会社]Chemicals Research Laboratories [化成品研究所ケミカル研究室]9-1, Oe-cho, Minato-ku, Nagoya 455-8502 JAPAN

URL:http://www.toray.co.jpContact: Yuji Ozeki (Senior Research Chemist)[尾関雄治] TEL +81 (52)-613-5276, FAX +81 (52)-613-5347e-mail: yuji_ozeki@nts.toray.co.jp

Purified 10 g sample

Toray Lot # S050808-3

(7,6)(7,5)

(8.,4)

(8,6)(9,4)

(6,5)

Toray Lot # S050808-3

(7,6)(7,5)

(8.,4)

(8,6)(9,4)

(6,5)

NarrowChirality

isolator

lenscollimator collimator

SAINT sampleisolator

isolator 980/ 1550coupler

40cmF:EDFA

10 mspot size

μ

980nmpump LD

70%

30% output

coupler

Saturable Absorbers:Application to Mode-Locked Fiber Lasers

Saturable Absorbers:Application to Mode-Locked Fiber Lasers

S. Yamashita, S. Maruyama, Y. Murakami, Y. Inoue, H. Yaguchi, M. Jablonski, S. Y. Set, Optics Letters, 29 (2004) 1581.

Photoluminescence of SWNTs suspended in airPhotoluminescence of SWNTs suspended in air

S. Iwasaki, Y. Ohno, Y. Murakami, S. Kishimoto, S. Maruyama, T. Mizutani (2005)

Vertically Aligned SWNTs on Quartz Substrate

Y. Murakami, S. Chiashi, Y. Miyauchi, M. Hu, M. Ogura, T. Okubo, S. Maruyama, Chem. Phys. Lett. 385 (2004) 298

0 500 1000 1500

100 200 300 400

2 1 0.9 0.8 0.7

Raman Shift (cm–1)

Inte

nsity

(arb

. uni

ts)

Diameter (nm)

10 μm

Narrow Chirality GrowthNarrow Chirality Growth

Catalysts and Alcohol Catalytic CVD MethodCatalysts and Alcohol Catalytic CVD Method

O

Molecular Dynamics Simulation for MechanismMolecular Dynamics Simulation for Mechanism500 Carbon & Ni108 : 2500K

1.2

nm

Y. Shibuta & S. Maruyama, Chem. Phys. Lett. 382 (2003) 381.

ACCVD Directly on Flat Surfaces (Dip-Coat)ACCVD Directly on Flat Surfaces (Dip-Coat)

Mo/Co 0.01wt % (each)Ethanol Solution

10 min soak& 4 cm/min

400 °C in Air, 5 min

Heat up to 800 °C in Ar/H2 (3 % H2)

(CH3COO)2Mo (CH3COO)2Co-4H2O

ACCVD

5 nm

Si or Quartz Substrate

1.5 nm MetalParticles

Y. Shibuta et al., CPL 382(2003)381.

bundle.pv

TEM images of Co-Mo catalysts on SiO2/Si after reductionTEM images of Co-Mo catalysts on SiO2/Si after reduction

M. Hu, Y. Murakami, M. Ogura, S. Maruyama, T. Okubo, J. Catalysis, 225 (2004) 230.

CoMoCoMoOx

Plan TEM [Quartz/catalyst/SiO2(10 nm)]

XTEM[Quartz/catalyst/glue

/catalyst/Quartz]

Slicing & PunchingMech. GrindingAr Ion Milling

Combinatorial Method to Prepare CatalystsNi Grows SWNTs

Combinatorial Method to Prepare CatalystsNi Grows SWNTs

S. Noda, Y. Tsuji, Y. Murakami, S. Maruyama, Appl. Phys. Lett., 86 (2005) 173106.

Ni: tNi = 0.22 nm

Co: tCo=0.081 nm

K. Kakehi, S. Noda, S. Chiashi, S. Maruyama (2006)

Best Condition

Combinatorial Method for (Co-Mo) CatalystsCombinatorial Method for (Co-Mo) Catalysts

S. Noda, H. Sugime, T. Osawa, Y. Tsuji, S. Chiashi, Y. Murakami, and S. Maruyama, Carbon 44 (2006) 1414.

Vertically Aligned

Combinatorial Method for (Co-Mo) Catalysts (2)Combinatorial Method for (Co-Mo) Catalysts (2)

10μm

100nm100nm

(III)(I) (II)

(I)

(II) (III)

H. Sugime, S. Noda, S. Maruyama, Y. Yamaguchi (2006).

Reduction temperature： 800℃Reaction temperature： 800℃Pressure of ethanol： 30TorrReaction time： 10min

Co/Mo [nm](I) 0.33/0.049(II) 0.19/0.13(III) 0.13/0.34

thin ← Mo → thick

thick↑Co↓

thin

Initial Reaction on CatalystInitial Reaction on Catalyst

Pulsed Valve

Target Disk

Waiting Room

Focused Laser Beam

He 10 atm

Expansion Cone

Cluster Beam

Cluster Source Nozzle for FT-ICRCluster Source Nozzle for FT-ICR

Turbopump

Gate Valve

Cluster Source

6 Tesla Superconducting Magnet

DecelerationTube

Front Door

Screen Door

Rear Door

Excite & DetectionCylinder

Electrical FeedthroughGas Addition

100 cm

Ionization Laser

Probe Laser

FT-ICR (Fourier Transform Ion Cyclotron Resonance)Mass Spectrometer

FT-ICR (Fourier Transform Ion Cyclotron Resonance)Mass Spectrometer

FT-ICR Study of Initial ReactionFT-ICR Study of Initial Reaction

800 1200

12 16 20 24

Mass (amu)

Inte

nsity

(arb

itrar

y)

(a)as injected

(b)0.2s

(c)0.5s

(d)1.0s

Number of Cobalt Atoms

C2H5OH (46amu)

C2HOH (42amu)

10 20 30

0.2

0.4

0.6

0.8

Number of Cobalt Atoms

reactive num. / total num.

this workSmalley et al.

10 20

0

2

4

6

Number of Cobalt Atoms

Inte

nsity

(–H

2 or –

2H2 /

che

mis

orpt

ion)

–2H2–H2

FT-ICR Chemical reaction of cobalt clusters (cation) with ethanol

FT-ICR Chemical reaction of cobalt clusters (cation) with ethanol

**

*

*820 840 860 880

14 15

Mass (amu)

Inte

nsity

(arb

itrar

y)

(a)C2H5OH

(b)C2H5OD

(c)CD3CH2OH

(d)C2D5OD

18

Number of Cobalt Atoms42

4amu

5amu

6amu

9amu

FT-ICR Study of Initial ReactionFT-ICR Study of Initial Reaction

5 10 15 20Number of Atoms

Rel

ativ

e R

eact

ion

Rat

e (a

rb. u

nit)

CobaltNickel

Iron

•Iron

Simple chemisorption

•Cobalt

Simple chemisorption

Dehydrogenation

•Nickel

Dehydrogenation

Single-Walled Carbon-13 Nanotubes (SW13CNTs)Single-Walled Carbon-13 Nanotubes (SW13CNTs)

Vacuum

Quartz test tube

Electric furnace

Quartz boat Dispersed metal particles embedded in Y-type zeolite

Isotopically-modifiedethanol (carbon-13) Coupler

Quartz tube

Flow channel

ACCVD technique optimized for the efficient production of SWNTs from very small amount of ethanol

1200 1400 1600

Inte

nsity

(arb

.uni

ts)

Raman Shift (cm–1)

(a) 12CH3 –12CH2 – OH

(b) 12CH3 –13CH2 – OH

(c) 13CH3 –12CH2 – OH

(d) 13CH3 –13CH2 – OH

0.988

0.974

0.9608

Comparison of Raman SpectraComparison of Raman Spectra

(a)

(b)

(c)

(d)

ααννα 1312)1(12 +−×= C

ααν131)1(

121

+−∝vib

Assuming…

Scaling factor

α： Ratio of 13C in a SWNT

α= 0.67

α= 0.31

α= 0

α= 1

Two carbon atoms in an ethanol molecule are not equally used for the SWNT formation in ACCVD process

200 300

Inte

nsity

(arb

.uni

ts)

Raman Shift (cm–1)

(a) 12CH3 –12CH2 – OH

(b) 12CH3 – 13CH2 – OH

(c) 13CH3 – 12CH2 – OH

(d) 13CH3 – 13CH2 – OH

0.970

0.986

13CH3－ 13CH2－ OH12CH3－ 13CH2－ OH13CH3－ 12CH2－ OH12CH3－ 12CH2－ OH

SWNTs with various amount of 13C abundance were synthesized from 3 types of isotope-modified ethanol

①②

Normal ethanol

Determination of ChiralityDetermination of Chirality

(6,5) SWNT with unique cap structure satisfying Isolated Pentagon Rule (IPR)

CVD Temperature DependenceCVD Temperature Dependence

(7,5) (7,6)

(6,5)

Emission wavelength (nm)

Exci

tatio

n w

avel

engt

h (n

m)

(7,5) (7,6)

(6,5)

Emission wavelength (nm)

Exci

tatio

n w

avel

engt

h (n

m)

(7,5) (7,6)

(6,5)

Emission wavelength (nm)

Exc

itatio

n w

avel

engt

h (n

m)

(7,5) (7,6)

(6,5)

Emission wavelength (nm)

Exc

itatio

n w

avel

engt

h (n

m)

Emission wavelength (nm)

Exc

itatio

n w

avel

engt

h (n

m)

(7,5) (7,6)

(8,6)

(8,4)

Emission wavelength (nm)

Exc

itatio

n w

avel

engt

h (n

m)

(7,5) (7,6)

(8,6)

(8,4)

850℃750℃650℃0.8 1

0

10

20

30

Tube diameter (nm)

Chi

ral a

ngle

(deg

.)

9,19,1

8,38,3

6,56,57,57,5

7,67,68,68,6

8,78,7

8,48,49,49,4

9,59,5

7,37,310,510,5

9,29,2 10,210,2

10,310,3 11,311,3

11,411,4

11,111,1

10,010,0 11,011,0

12,112,1

12,212,2

13,013,0

9,19,1

8,38,3

6,56,57,57,5

7,67,68,68,6

8,78,7

8,48,49,49,4

9,59,5

7,37,310,510,5

9,29,2 10,210,2

10,310,3 11,311,3

11,411,4

11,111,1

10,010,0 11,011,0

12,112,1

12,212,2

13,013,00.7 0.8 0.9 1

0

10

20

30

Tube diameter (nm)C

hira

l ang

le (d

eg.)

9,19,1

8,38,3

6,56,57,57,5

7,67,68,68,6

8,78,7

8,48,49,49,4

9,59,5

7,37,310,510,5

9,29,2 10,210,2

10,310,3 11,311,3

11,411,4

11,111,1

10,010,0 11,011,0

12,112,1

12,212,2

13,013,0

9,19,1

8,38,3

6,56,57,57,5

7,67,68,68,6

8,78,7

8,48,49,49,4

9,59,5

7,37,310,510,5

9,29,2 10,210,2

10,310,3 11,311,3

11,411,4

11,111,1

10,010,0 11,011,0

12,112,1

12,212,2

13,013,00.7 0.8 0.9 1

0

10

20

30

Tube diameter (nm)

Chi

ral a

ngle

(deg

.)

9,19,1

8,38,3

6,56,57,57,5

7,67,68,68,6

8,78,7

8,48,49,49,4

9,59,5

7,37,310,510,5

9,29,2 10,210,2

10,310,3 11,311,3

11,411,4

11,111,1

10,010,0 11,011,0

12,112,1

12,212,2

13,013,0

9,19,1

8,38,3

6,56,57,57,5

7,67,68,68,6

8,78,7

8,48,49,49,4

9,59,5

7,37,310,510,5

9,29,2 10,210,2

10,310,3 11,311,3

11,411,4

11,111,1

10,010,0 11,011,0

12,112,1

12,212,2

13,013,0

Carbon source : Ethanol, CVD time : 10min

Resasco’sCoMoCAT

S. M. Bachilo et al., JACS,

125 (2003) 11186.

Chirality dependent quantum yieldChirality dependent quantum yield

Y. Oyama, R. Saito, K. Sato, J. Jiang, Ge.G. Samsonidze, A. Gruneis, Y. Miyauchi, S. Maruyama, A. Jorio, G. Dresselhaus, M.S. Dresselhaus, Carbon in press.

(10,2)(8,3)

(6,4)

(12,1)

0.6 0.8 1 1.2 1.4

100

102

104

Nanotube diameter (nm)

Num

ber o

f IPR

Sat

isfy

ing

Cap

Stru

ctur

es

(10,10)

(5,5)

(6,5)&(9,1)

(9,9)

(8,8)

(7,7)

(6,6)

IPR (Isolated Pentagon Rule)-Satisfying Cap StructureIPR (Isolated Pentagon Rule)-Satisfying Cap Structure

armchair

zigzag

(6,5)(9,1)

T. Yu et al., Fullerene Sci. Tech., 7, 769 (1999).

7 7.5–7.4

–7.2

–7

Pot

entia

l ene

rgy

(eV

/ato

m)

(5,5)

(9,0)

(6,5)

(9,1)

(6,5)

(9,1)

(5,5)

(9,0)

Diameter(Å)

Energy of Nanotube Cap StructureEnergy of Nanotube Cap Structure

Brenner potential

(6,5) d = 7.64Å

(9,1) d = 7.64Å

(9,0) d = 7.20Å

(5,5) d = 6.93ÅWith Cap

Tube Only

PL peaks other than Eii ~ Phonon SidebandPL peaks other than Eii ~ Phonon Sideband

12C

(10,2)

I

II

13C

12C

(6, 5)

(7, 5)(8, 3)

1.5

2

2.5

Emission intensity (arb. units)

Exc

itatio

n en

ergy

(eV

)

(7, 5) E 22

(6, 5) E 22

x 5

(10, 2) E 22

(8, 3) E22

Y. Miyauchi and S. Maruyama, Phys.Rev. B, in press.

Phonon sideband

Phonon sideband

Phonon sideband and Raman

Ph

Ph

Ph

?

?

?

?

V. Perebeinos, J. Tersoff, P. Avouris, PRL 94, 027402 (2005).

PL peaks other than EiiPL peaks other than Eii

G-band (Raman)

Rayleigh

(7,5)(7,6)

(6,5)

(8,3)

(10,2)

E11emission

E11

E11 + phonon

E22 + phonon

E22

E12, E 21

Background for perpendicular excitation

⊥

//

//

//

//

⊥

Emission energy

Exci

tatio

n en

ergy

G-band

Rayleigh

G’-band

PL map of SWNTs (ACCVD SWNTs) Schematic of PL peak positions in a PL map

Y. Miyauchi, PhD thesis (2006)

Vertically Aligned SWNTs and Growth Process

10 µm

0 5 10 150

2

4

0

10

20

30

CVD time [min]

Abso

rban

ce [

– ]

VA–S

WN

T fil

m th

ickn

ess

[ μm

]

Stop herefor 25

μm

Stop herefor

10 μm

In-situ Measurement of Film ThicknessIn-situ Measurement of Film Thickness

Mai

n dr

ain

tube

Sub

drai

n tu

be

Quartz tubeElectric furnace

Pirani gauge

Vacuum pump

Substrate

Ethanol tank

Hot bath

Pressure manometer

Ar-H2

mixed gas

LaserPrism

or Mirror

Quartz tube

Electric furnace

SubstrateLaser light detector

PCUSB cable

Gas flow

S. Maruyama et al., CPL 403 (2005) 320.

0 10 20 300

0.5

1

0

2

4

6

8

CVD time (min)

Abs

orba

nce

VA

SW

NT

film

thic

knes

s (μ

m)

0 10 20 300

0.5

1

0

2

4

6

8

CVD time (min)

Abs

orba

nce

VA

SW

NT

film

thic

knes

s (μ

m)

η0 = 1.9x10–4 m2 mol–1

τ = 204 s

ε∞ = 28.0 m2 mol–1

Fitting Lines

η0 = 1.1x10–4 m2 mol–1

τ = 300 s

Catalyst-Consumption Growth ModelCatalyst-Consumption Growth Model

τηη−=

dtd

⎟⎠⎞⎜

⎝⎛ −=

−ττη

tetC 1)( 0

Growth Model

Catalyst Activity η

Carbon Mass C(t)

Additional Burning of SWNTsAdditional Burning of SWNTs

0 30 600

0.1

0.2

0.3

0

1

2

CVD time (min)

Abs

orba

nce

VAS

WN

T fil

m th

ickn

ess

(μm

)

η0 = 3.4x10–5 m2 mol–1

τ = 250 s

Ethanol Stopped

Detachment of VA-SWNT films with hot waterDetachment of VA-SWNT films with hot water

Y. Murakami and S. Maruyama, Chem. Phys. Lett. 422(2006) 575.

(a) As-grown on quartz

(b) Re-attached on Si

0.5 mm

a

0.5 mm

Hidetsugu Shiozawa & Thomas Pichler (IFW-Dresden e.V.),Erik Einarsson, Shigeo Maruyama

TEM Image from Top of CarpetTEM Image from Top of Carpet

Laser ACCVD and in situ Raman MeasurementsLaser ACCVD and in situ Raman Measurements

S. Chiashi, M. Kohno, Y. Takata, S. Maruyama, (2005)

0 2 4 6 8 100

200

400

600

800

1000

Time (min)

Inte

nsity

(arb

. uni

ts)

Tem

pera

ture

(°C

)

τ=100 (s)Δt=42 (s)

ethanol gas supply

(c) temperature

(b) silicon

(a) the G–band

⎥⎦

⎤⎢⎣

⎡⎟⎠⎞

⎜⎝⎛ Δ−

−=τ

ttAy exp1 τ =100 ∼ 200 (s)Δt=30∼40 (s)

Ar laser objective lens

collective lens

ethanolgas

Raman excitation laser(488, 514, 633 nm)

Laser ACCVD and in situ Raman MeasurementsLaser ACCVD and in situ Raman Measurements

S. Chiashi, M. Kohno, Y. Takata, S. Maruyama, (2005)

0 2 4 6 8 100

200

400

600

800

1000

Time (min)

Inte

nsity

(arb

. uni

ts)

Tem

pera

ture

(°C

)

τ=100 (s)Δt=42 (s)

ethanol gas supply

(c) temperature

(b) silicon

(a) the G–band

⎥⎦

⎤⎢⎣

⎡⎟⎠⎞

⎜⎝⎛ Δ−

−=τ

ttAy exp1 τ =100 ∼ 200 (s)Δt=30∼40 (s)

Ar laser objective lens

collective lens

ethanolgas

Raman excitation laser(488, 514, 633 nm)

10–2 10–1 100101

102

103

Ethanol Gas Pressure (Torr)

Incu

batio

n Ti

me,

Δt (

s)Δt=P–1.6

AcknowledgementsAcknowledgementsDr. Y. Murakami, Mr. Y. Miyauchi, Dr. S. Chiashi, Mr. Erik Einarsson, Mr. T. Nishii, Dr. T.

Shimada (Nagoya Univ.), Prof. M. Kohno (Kyushu Univ.) , Prof. S. Inoue (Hiroshima Univ.), Prof. Y. Shibuta, Dr. J. Shiomi, Dr. H. Yamaguchi (Nagoya Univ.)

Mr. K. Ishikawa, Mr. M. Oba, Mr. D. Yoshimatsu, Mr. K. Koizumi, Mr. S. Hirama, Mr. M. Kadowaki, Dr. M. Hu, Prof. T. Okubo, Prof. S. Noda @ Chem. Synthesis

Prof. R. E. Smalley, Prof. B. Weisman, Prof. J. Kono @ Rice Univ.Prof. H. Shinohara, Prof. Y. Ohno, Prof. T. Mizutani @ Nagoya Univ.,

Prof. K. Matsuda @ Kyoto University, Prof. R.Saito @ Tohoku Univ., Prof. S.Okada @ Tsukuba Univ., Prof. T. Miyake @ AISTProf. M. Endo @ Sinshu University, Dr. M. Yudasaka @ NEC, Prof. M. Dresselhaus @

MIT, Prof. A. Jorio @ UFMG, Prof. S. Suzuki, Prof. Y. Achiba @ Tokyo Metropolitan Univ., Prof. H. Kataura @ AIST, , Dr. H. Shiozawa & T. Pichler @ IFW-Dresden e.V.

Mr. H. Tsunakawa @ University of Tokyo, Mr. T. Sugawara @ University of TokyoMr. M. Sunose @ Seki-Tech.

Mr. N. Masuyama@ J-Power Co. Ltd., Mr. Y. Kondo@ Konica-Minolta, Mr. S. Watanabe, Ms. M. Nakagawa, Mr. R. Tamochi @ Hitachi Science Systems

JSPS, MEXT, Toray, XNRI, J-Power, DENSO, Konica-Minolta, Tokyo-Gas, SEL, Toso

Professor Richard E. Smalley at Rice University (1943-2005)Professor Richard E. Smalley at Rice University (1943-2005)

1943: Born in Akron, Ohio on June 61976: PhD from Princeton,

Assistant Professor at RiceLaser Vaporization Cluster Beam

1984: Discovery of C601996: Nobel Prize in Chemistry with Kroto and Curl1996: Bulk Production of SWNTs

Then HiPco Process2000: Testified for National Nanotechnology Initiative2000: Found Carbon Nanotechnology Inc.

Application of Nanotechnology to Energy Problem2005: Died at 62 on October 28, 2005

1990

20012001

20052005

Catalytic CVD Synthesis of SWNTs from FullereneCatalytic CVD Synthesis of SWNTs from Fullerene

vacuumvacuumvacuum

Quartz plate

Quartz tubeFurnace A

Furnace B

Dispersed metal particles (Fe/Co 2.5wt%) embedded in Y-type zeolite

Thermocouple

Inorganic adhesive

Quartz woolQuartz test tube

FullereneC60 or C70

0 200 400 600

200

400

600

deg

C [℃

][s]

Temperature up curve of TC

(CH3CO2)2Fe(CH3CO2)2Co-4H2O etc.

Catalysts

Supports

Zeolite USYHSZ-390HUA

Temperature: Furnace B 825℃Time: 10min

CCVD Generation of SWNTs from FullereneCCVD Generation of SWNTs from Fullerene

Fullerene

Up-StandingBundle

Up-StandingBundle

200 300

1.8

2

2.2

2.4

2.6

1 0.9 0.8Nanotube Diameter (nm)

Ene

rgy

Sep

arat

ion

(eV

)

488 nm

514.5 nm

633 nm

Inte

nsity

(arb

.uni

ts)

Raman Shift (cm–1)

(a) C70, 488

(b) C70, 514.5(c) C70, 633

(d) EtOH, 488

(e) EtOH, 514.5

(f) EtOH, 633* *

S. Maruyama et al, Chem. Phys. Lett., 375 (2003) 553.

Water Assisted Super-Growth

Iijima Group (K. Hata et al., Science, 2004)

2.5 mm height Catalysts: Al2O3 (10 nm)/Fe(1 nm) Buffer: Ar (99.9999%) or He (99.9999%) with 40% H2 (99.99999%) Water:175 ppmSource: 100 sccm ethylene (99.999%) CVD Temp.: 750°C x 10 min

Super Growth by Kawarada GroupSuper Growth by Kawarada Group

G. Zhong, JJAP 44 (2005) 1558.

Point arc Microwave Plasma CVD0.7nmAl2O3/0.5nmFe/5-70nmAl2O3 Catalysts

66kg/m3

270 micron/h

isolator

lenscollimator collimator

SAINT sampleisolator

isolator 980/ 1550coupler

40cmF:EDFA

10 mspot size

μ

980nmpump LD

70%

30% output

coupler

Saturable Absorbers:Application to Mode-Locked Fiber Lasers

Saturable Absorbers:Application to Mode-Locked Fiber Lasers

S. Yamashita, S. Maruyama, Y. Murakami, Y. Inoue, H. Yaguchi, M. Jablonski, S. Y. Set, Optics Letters, 29 (2004) 1581.

Polarized Optical Absorption of VA-SWNTs (2) Polarized Optical Absorption of VA-SWNTs (2)

Y. Murakami, E. Einarsson, T. Edamura, S. Maruyama: Phys. Rev. Lett., 94, 087402(2005)

0 2 4 60

1

2

Energy (eV)

Abs

orba

nce

0 2 4 60

1

2

Energy (eV)

Abs

orba

nce

0 2 4 60

1

2

Energy (eV)

Abs

orba

nce

0 2 4 60

10

20

30

σ (m

2 /mol

e C

)

Energy (eV)

σ||

σ_|_

(b)

0 30 60 900

1

2

Abs

orba

nce

θ (deg)

4.5 eV

5.3 eV2.8 eV4.0 eV

(a)

0 2 4 60

10

20

30

σ (m

2 /mol

e C

)

Energy (eV)

σ||

σ_|_

(b)

0 30 60 900

1

2

Abs

orba

nce

θ (deg)

4.5 eV

5.3 eV2.8 eV4.0 eV

(a)

( )⎭⎬⎫

⎩⎨⎧ −

++= ⊥⊥ S

ηηηησ ||

||||

22

31

⎟⎟⎠

⎞⎜⎜⎝

⎛ −−+= ⊥

⊥⊥ Sηη

ηησ ||||2

31

θ2sin

le //le ⊥

100 200 300

2 1 0.9 0.8

Inte

nsity

(arb

.uni

ts)

Raman Shift (cm–1)

Diameter (nm)

488 nm

Anomalous Raman Scattering Anomalous Raman Scattering

0

2

4

Nor

mal

ized

pea

k in

tens

ity [–

]

160 cm–1

203 cm–1

145 cm–1

257 cm–1

242 cm–1

180 cm–1

From top 45° Parallel488 nma

le //

le ⊥

Y. Murakami, S. Chiashi, E. Einarsson, S. Maruyama: Phys. Rev. B, 7, 085403(2005)

InGaAs Detector

Photoluminescence Spectroscopy of SWNTsPhotoluminescence Spectroscopy of SWNTs

M. J. O’Connell et al., Science 297 (2002) 593

S. M. Bachilo et al., Science 298 (2002) 2361

(7,5)

11νh22νh D2O 1.1g /cm3

1.0g / cm3

SDS

Strong sonicationSuper centrifuge 380,000g x 1h

E22

E11

(E11)

(E22)

–1

0

1

Ene

rgy

(eV

)

11νh

v1 v2

c1 c2

h

e

22νh