May 16, 2012 for Shoshin Study Tour 2012 - Study Association Arago (the University of Twente, Netherlands)

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Division of Molecular Materials Science

Research Center for Low Temperature and Materials Sciences, Kyoto University

SSO

O

SS

O

OS

SO

O

SS

S

SO

O S

S CH3

SS

O

O

SS

ClSS

O

O S

S

SS

SS

Synthesis of Functional Materials

Structural Analysis & Physical Properties examination

Design of New Materialshttp://mms.ltm.kyoto-u.ac.jp/

index_e.html

1980s: Organic Superconductors

Se

Se

Se

SeH3C

H3C CH3

CH3

S

SS

S S

S

S

S

Q1D Superconductors

max. Tc = 1.4 K (AP)

2D Superconductorsmax. Tc = 12.3 K (AP)

History of Molecular Conductors1954 Organic

Semiconductor

• Br2

1960s 1D Organic Metals

S

S

S

S

NC

NC

CN

CN

Increment of Dimensionality

1990s: 3D Molecular Superconductors

max. Tc = 33 K (AP)

Molecular Degree of Freedom

Lattice point Simply a

point Size Shape Functionality

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CC S

CSOH2C

H2C OC

S CCS

H

H

CC S

CSOH2C

H2C OC

S CCS

H

H CC S

CSOH2C

H2C OC

S CCS

H

H+

CC S

CSOH2C

H2C OC

S CCS

H

HPF6

2

+ PF6e

(EDO-TTF)2PF6

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SSO

O

SS

O

OS

SO

O

SS

S

SO

O S

S CH3

SS

O

O

SS

ClSS

O

O S

S

SS

SS

Charge-Transfer Complex Formation Molecular Conductors

To endow the electrical conductivity to molecular based materials, the charge-transfer complex is formed by treated with donor/ acceptor molecules or by electrochemical method.

Metal

Insula

tor

Trans

ition

Electro-oxidation

for example

plan

ar: 0

.8º,

2.1º

ben

t:

11.1

º, 7.

9º

q 1, q

2:

6.0

º , 0

.3º

Distinct Molecular Deformation

PF6 RotationIsotropic

(EDO-TTF)2PF6 — Above and Below TMI (280 K)

Overlap IntegralUniform

from Bond Lengt

h0.5+

Molecular Deformation is regarded as the Origin to Mix Metal-Insulator Transition Mechanisms (Multi-instability).

Alternate

Peierls

(Overlap Integral 103)

1+/0

Charge Orderin

g

Uniaxial

Order-Disorde

r

- 4 -A. Ota et al., J. Mater. Chem., 12(9), 2600-2602 (2002)

Time Delay

Probe (white light)Pump (1.55 eV= 12.5 103 cm-1)

Thermal Transition PIPT

1.55

eV

1.70

eV

1.38

eV

1.55

eV

1.70

eV

1.38

eV

Sample

Photo-Induced Phase Transition (PIPT) of (EDO-TTF)2PF6

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Probe 1.70 eV (13.7 103 cm-1)

Probe 1.38 eV (11.1 103 cm-1)

Responce < 0.1 psRelaxation to meta-stable state ≈ 1.5 ps

1 photon / 50-500 moleculesUltra-fast & Highly Efficient PIPT

MaterialM. Chollet et al., Science, 307, 86-89 (2005) [Erratum: 312, 697 (2006)]H. Yamochi, S. Koshihara, Sci. Technol. Adv. Mater., 10(2), 024305/1-6 (2009)

B: Thermally Induced Metal

Three-level Rate Equation

A: (1010) phaseFluctuated Charge Order

C: Charge Randomization

+ Photo Induced Carrier

+ .....

InsulatorLow Temp. Phase

0.1 - 1 ps

10 ps order

100 ps order

PI Process over 100 ps

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<Recent Result>

PIPT Route is Analyzed.

N. Fukazawa et al., J. Phys. Chem. C, 116(9), 5892-5899 (2012)

208. D.V. Konarev et al., Inorg. Chem., 51(6), 3420–3426 (2012)207. D.V. Konarev et al., New J. Chem., 35(9), 1829-1835 (2011)197. D.V. Konarev et al., Inorg. Chem., 49(8), 3881–3887 (2010)

213. T. Hiramatsu et al., Physica Status Solidi C, 9(5), 1155-1157 (2012)212. M. Ishikawa et al., Physica Status Solidi C, 9(5), 1143-1145 (2012209. N. Fukazawa et al., J. Phys. Chem. C, 116(9), 5892-5899 (2012)204. K. Onda et al., Physica B, 405(11), S350-S352 (2010)202. X.F. Shao et al., Physica B, 405(11), S75-S78 (2010)199. T. Murata et al., Physica B, 405(11), S45-S48 (2010)

211. H. Yamochi et al., Physica Status Solidi B, 249(5), 1012-1016 (2012)210. T Ishikawa et al., J. Phys.: Condens. Matter, 24(19), 195501/1-9 (2012)206. T. Haneda et al., J. Mater. Chem., 21(5), 1621-1626 (2011)205. G. Saito et al., Bull. Chem. Soc. Jpn., 83(12), 1462–1480 (2010)203. Y. Nakano et al., Physica B, 405(11), S198-S201 (2010)201. T. Shirahata et al., Physica B, 405(11), S61-S64 (2010)200. Y. Nakano et al., Physica B, 405(11), S49-S54 (2010)

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Recent Publications ▪ ▪ ▪ ▪ ▪ many corroborations with other laboratories

Other Materials

S

SO

O S

S& the derivatives

(C60) Materials