1

Structural Study of Carbon Nanomaterials

under High Pressure

Bingbing Liu

刘冰冰

State Key Lab of Superhard Materials, Jilin University

吉林大学超硬材料国家重点实验室

3rd GCOE international Symposium, 2011-02-18, Sendai

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Carbon family

Peapod

Graphene

Superhard ―ball‖

~800GPa

Superhard ―tube‖

~TPa

3

High Pressure

Classic Example: Carbon

Graphite Diamond

P

3

4

High Pressure

Classic Example: Carbon

Graphite Diamond

P

3

High Pressure Cell

Large volume press

5

Diamond Anvil Cell

~100 GPa

High Pressure Cell

Large volume press

CONVENTIONALMEGABAR DIAMOND

ANVIL CELL

50 GPa ~200 mm ~10 nl (10-9 l)

200 GPa ~20 mm ~1 pl (10-12 l)

P d Volume

d

6

Laser heating Raman,

Brillouin Spectrometer

High pressure Raman Spectrometer

(4 Lasers)

High pressure XRD HP -Electric property

measurement

High pressure IR spectrometer

New Generation of DAC Integrated Platform for in situ Ultrahigh-Pressure Structure and Physical Property Study

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Carbon family

Peapod

Graphene

Superhard ―ball‖

~800GPa

Superhard ―tube‖

~TPa

8

Outline

Peapod (C60 inside SWNTs)

High pressure induced polymerization and rotational dynamics of C60 inside SWNTs

(NIR Raman at LT and HP)

Hydrogenated fullerenesStructures of C60H18 and C70H38 under high pressure

( XRD and IR)

Summary

2011-2-24

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Background---High pressure induced polymerization in C60

High

pressure

High

temperature

Liu BB* et al

Adv. Mater., 18 (2006) 1883;

Appl. Phys. Lett ,91 (2007) 103112;

89 (2006) 181925

Diamond & Rel. Mater.17 (2008) 620 Raman and PL Spectra for polymeric structure of C60 induced

by high pressure and high temperature

“Soft” crystal, Rotating molecule

Covalent ―hard‖ bonds have been

introduced in C60 nanocrystals by HPHT

Well-controlled polymeric structures

Unusual NIR PL properties

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HP polymerization of C60 with the confinement of nanotubes

Dimerization and one-chain polymeric structure can be induced by only application of different

high pressure with the confinement of SWNTs.

? How…..

Dimer (1.2GPa)one-chain(23Gpa)

High pressue only!

Zou YG, Liu BB* et al, Phys. Rev. B (2008)

Peapod-C60@SWNTs ---- Nano confinement model

High pressure Raman Spectrometer

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C60 inside SWNTs

Fixed

Free rotation?

Bulky C60 crystal

Free rotation >260 K

Librational rotation >85 K

Fixed low temperature

still unclear !Rotational dynamics of C60 in SWNTs-

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C60 inside SWNTs

Fixed

Free rotation?

Bulky C60 crystal

Free rotation >260 K

Librational rotation >85 K

Fixed low temperature

still unclear !Rotational dynamics of C60 in SWNTs-

Inelastic neutron scattering

Rols et al., Phys. Rev. Lett, 101, 065507(2008)

NMR

Matsuda et al, PRB 77,075421(2008)

Rotating , but no detailed info!

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RBM —breathing mode of SWNTs—diameter

Ag(2) —pentagon pinch mode of C60—monomer or polymer

IFM —radial vibration of C60—Rotational state?

RBM

?

Ag(2)

G-band

Rotational dynamics of C60 in SWNTs - Raman

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The whole Raman spectrum of peapod at Room temperature

RBM

Ag(2)

G-band

Rotational dynamics of C60 in SWNTs - NIR Raman

830nm

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#Chadli et al，Physica 2005;358:226.（theory）

pentagon

hexagon

C60 Peapod

ω(cm-1)

C60@(10,10)

ω(cm-1)#

Hg(1) 272256, 292,

306, 326

274, 282,

289

Hg(2) 433 434, 452 446, 452

Ag(1) 497 493, 524

Hg(3) 710 709 719

Hg(4) 773 771 794

Strong interaction

Rotational dynamics of C60 in SWNTs - IFMs

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IFMs for Peapod at low temperature Intensity ratio of Hg2/Hg4

Rotational dynamics of C60 in SWNTs – IFMs at low T

Interaction：pentagon > hexagon

？C60 s are not rotating freely but have a preferred relative orientation

which C60s are subjected to the strongest interaction with tubes

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Pentagonal orientation

Rotational dynamics of C60 in SWNTs – Low energy states

Hexagonal orientation

C60 inside SWNTs:

Hexagonal orientation:

pentagons have a stronger interaction

with tubes than hexagons

Michel etal, PRL 95, 185506 (2005)

Verberck etal , PRB, 74, 045421 (2006)

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Hg(3) and Hg(4) are splitted into several peaks due to C60-C60 interactions

NIR Raman spectra of polymeric peapod-IFMs

Hg(1)andHg(2):intensity increases

Uniaxial rotation should be difficult for rotation Rule out uniaxial rotation

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Theoretical simulation

Discover Module

(Materials Studio)

Compass force field

Energy of C60 confined in SWNTs with different diameter

New picture：

ratched rotating

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a) hexagonal orientation

1 hexagon faces to double bond

b) hexagonal orientation

1 hexagon faces to single bond

c) pentagonal orientation

1pentagon faces to vertex angle

d) pentagonal orientation

1 pentagon faces to single bond

Rotational states of C60 with different orientations-polymerization

Polymeric state is a special state of hexagonal orientation

Zou YG , Liu BB* et al, PNAS 106 (2009)22315

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Outline

Peapod (C60 inside SWNTs)

High pressure induced polymerization and rotational dynamics of C60 inside SWNTs

(NIR Raman at LT and HP)

Hydrogenated fullerenesStructures of C60H18 and C70H38 under high pressure

( XRD and IR)

Summary

2011-2-24

222011-2-24

Hydrofullerenes: C60Hx

232011-2-24

TThh

DD3d3d(CK)(CK)

DD3d3d

TT

SS66

MostMost StableStable

C60H36

Hydrofullerenes: C60Hx

242011-2-24

TThh

DD3d3d(CK)(CK)

DD3d3d

TT

SS66

CC3V3V

MostMost StableStable

C60H18 C60H36

Hydrofullerenes: C60Hx

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Synthesis and characterization of C60H18

C60 power(0.5-1g,99.5%)C60 power(0.5-1g,99.5%)

H2H2

Alumina container

(3cm3) 673K,10h,

100bar

Alumina container

(3cm3) 673K,10h,

100bar

2011-2-24

C60H18

95 wt % purity of

single C3V isomer

High Temperature and High pressure synthesis method

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Crystal structure of C60H18

Fcc a=14.56 ± 0.04Å Fcc a=14.11Å

Keep in Fcc to 32GPa Amorphous at 28GPa

Synchrotron x-ray diffraction pattern of C60H18 under different pressures

C60H18 C60

T. Horikawa et al

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Bulk modulus B0

(a) Pressure dependence of d values for C60H18, (b) Pressure dependence of the relative unit cell volume of C60H18

C60 Bulk

Modulus

B0 =21±1.16 GPa

B0' = 6.68±0.25

C60H18 is 40 % less

compressible than C60

Protected by H atoms

C60H18

282011-2-24

IR experiment under high pressure

Customerized high pressure IR spectrometer

292011-2-24

Experimental (curve a) and calculated by DMOL3 mid-IRabsorption spectra (curve b)

of C60

H18

at ambient pressure

IR of C60H18 at ambient pressure

IR spectra : experimental data

302011-2-24

Experimental (curve a) and calculated by DMOL3 mid-IRabsorption spectra (curve b)

of C60

H18

at ambient pressure

Breathing vibrational modes of the carbon cage

C-H stretching vibrations

IR of C60H18 at ambient pressure

IR spectra : experimental data (a) and theoretical simulation (b) DMOL3

312011-2-24

Experimental (curve a) and calculated by DMOL3 mid-IRabsorption spectra (curve b)

of C60

H18

at ambient pressure

C-H stretching vibrations

IR of C60H18 at ambient pressure

IR spectra : theoretical simulation (b) DMOL3

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IR of C60H18 under high pressure

V1V2 V3

Mid-IR absorption spectra of C60H18 under high pressures.

332011-2-24

Different IR Bands Shift with pressure

V1

V2

V3

V3

V2

V1

342011-2-24

Different IR Bands Shift with pressure

1612 cm-1

1471 cm-1

352011-2-24

Different IR Bands Shift with pressure

1201 cm-1

1272 cm-1

362011-2-24

Different IR Bands Shift with pressure

Three bands 2800 cm-1 to 3000 cm -1

Shift to low wave numbers

V1 ~ - 0.5cm-1/GPa

V2 ~ - 3 cm-1/GPa

V3 ~ -2 cm-1/GPa

Van der Waals interactions between

H atoms and neighboring molecular

cages which acts as a spring between

the molecular cages

Breathing-like vibrational modes

of the carbon cage

1474 and 1611 cm-1 only linked to

carbon atoms

1201 and 1272 cm-1 are related with

vibrations of carbon atoms with bonds

to hydrogen atoms which shift slower

than above.

372011-2-24

XRD and IR spectra for C60H18 after decompression

Honglei Ma Bingbing Liu* etl. J.Phys.Chem.Lett. 1(2010)714

Reversible change in structure

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C70H38 a more complicated hydrofullerene

Low Symmetry Structure Low Symmetry Structure c2 T.. Wagberg et al

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Synthesis and characterization of C70H38

C70 powerC70 power

H2H2

673 K

100 bar for 72 h

673 K

100 bar for 72 h

C70H38 95wt %

purity of the

single C2 isomer

T.. Wagberg et al

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Crystal structure of C70H38

2011-2-24

Phys. Rev. B 53, 8180–8183 (1996)

XRD patterns recorded from unreacted C70(top) and

hydrogenated C70with C70H38 as major component

Supporting information of

Angew. chem. Int. ed. 2008, 47, 2796-2799

C70H38 the cell volume expanded by ~17%~17%

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Summary

Polymerization is induced by high pressure

a novel behavior---a ratcheted rotation with a preferred “hexagonal

orientation” which provides new insight to understand the behavior

of molecules confined in one-dimensional systems.

With the presence of hydrogen, structural change of fullerene is

protected by hydrogen under high pressure

Two IR region shift to opposite directions, indicating a change in the

interaction between hydrogen and neighboring cages which could

explain the low compressibility of the structure under high pressure.

C60@SWNTs-Peapod

Hydrofullerenes -C60H18 and C70H38

High pressure is an effective method to obtain new carbon nanomaterials

with novel structures and to investigate new phenomenon

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Acknowledgement

Collaborator

Prof. Guangtian Zou, Prof. Tian Cui , Prof. Bo Zou (Jilin Univ.)

Prof. Bertil Sundqvist and Dr. T. Wagberg (Umea Univ., Sweden)

Dr. Zhenxian Liu, Dr. Ho-Kwang Mao（Carnegie Institute of

Washington, USA)

Dr. Zhiqiang Chen (NSLS ~X17C)

Dr. Jing Liu (Institute of High Energy Physics, CAS)

GroupMingguang Yao, Quanjun Li, Ran Liu

Yonggang Zou, Honglei Ma, Xuemei Zhang, Dedi Liu

Financially supported by

973 project, NSFC, MOE, Swedish Research Council

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Thank you!