Infrared and raman studies of charge ordering in organic conductors, BEDT-TTF salts with quarter-filled bands

Crystals

Volumn 2, Issue 3, 2012, Pages 1291-1346

  Yakushi, Kyuya ^a  

^a TOYOTA PHYSICAL AND CHEMICAL RESEARCH INSTITUTE   (Japan)

Author keywords

BEDT TTF; Charge order; Infrared and Raman spectroscopy; Optical conductivity; Organic conductor; Vibrational spectroscopy

Indexed keywords

EID: 84879916500     PISSN: None     EISSN: 20734352     Source Type: Journal    
DOI: 10.3390/cryst2031291     Document Type: Review

References (182)

1. 3. Chem. Phys. Lett. 1974, 25, 409-412.
2. Bozio, R.; Girlando, A.; Pecile, C. Vibrational analysis of spectra of quinoid molecular ions. J. Chem. Soc. Faraday Trans. 1975, 71, 1237-1254.
3. Matsuzaki, S.; Kuwata, R.; Toyoda, K. Raman spectra of conducting TCNQ salts; estimation of the degree of charge transfer from vibrational frequencies. Solid State Commun. 1980, 33, 403-405.
4. Chappell, J.S.; Bloch, A.N.; Bryden, W.A.; Maxfield, M.; Poehler, T.O.; Cowan, D.O. Degree of charge transfer in organic conductors by infrared absorption spectroscopy. J. Am. Chem. Soc. 1980, 103, 2442-2443.
5. Kagoshima, S.; Ishiguro, T.; Anzai, H. X-ray scattering study of phonon anomalies and superstructures in TTF-TCNQ. J. Phys. Soc. Jpn. 1976, 41, 2061-2071.
6. F anomaly in TTF-TCNQ. J. Phys. Soc. Jpn. 1977, 43, 424-436.
7. F, and spin-Peierls fluctuations in organic metal: Tetrathiafulvalene-Tetracyanoquinodimethane (TTF-TCNQ). Phys. Rev. 1978, 17, 3099-3103.
8. Hubbard, J. Generalized wigner lattices in one dimension and some applications to tetracyanoquinodimethane (TCNQ) salts. Phys. Rev. 1978, 17, 494-505.
9. 2Ag. Phys. Rev. Lett. 1998, 80, 4737-4740.
10. Seo, H.; Fukuyama, H. Antiferromagntic phases of one-dimensional quarter-filled organic conductors. J. Phys. Soc. Jpn. 1997, 66, 1249-1252.
11. Chow, D.S.; Zamborszky, F.; Alavi, B.; Tantillo, D.J.; Baur, A.; Merlic, C.A.; Brown, S.E. Charge ordering in the TMTTF family of molecular conductors. Phys. Rev. Lett. 2000, 85, 1698-1701.
12. Moldenhauer, J.; Horn, C.; Pokhondnia, K.I.; Schweitzer, D.; Heinen, I.; Keller, H.J. FT-IR absorption spectroscopy of BEDT-TTF radical salts: Charge transfer and donor-anion interaction. Synth. Metal. 1993, 60, 31-38.
13. 3. J. Phys. Soc. Jpn. 1995, 64, 1877-1880.
14. 3. J. Phys. Chem. Solid 2001, 62, 393-395.
15. Miyagawa, K.; Kawamoto, A.; Kanoda, K. Charge ordering in a quasi-two-dimensional organic conductor. Phys. Rev. 2000, 62, R7679-R7682.
16. Seo, H. Charge ordering in organic ET compounds. J. Phys. Soc. Jpn. 2000, 69, 805-820.
17. McKenzie, R.H.; Merino, J.; Marston, J.B.; Sushkov, O.P. Charge ordering and antiferromagnetic exchange in layered molecular crystals of the θ-type. Phys. Rev. 2001, 64, 085109:1-085109:11.
18. 2X. Sci. Technol. Adv. Mater. 2009, 10, 024312:1-024312:11.
19. Mazumdar, S.; Clay, R.T.; Campbell, D.K. Bond-order and charge-density waves in the isotropic interacting two-dimensional quarter-filled band and the insulating state proximate to organic superconductivity. Phys. Rev. 2000, 62, 13400-13425.
20. 2X materials. J. Phys. Soc. Jpn. 2002, 71, 1816-1819.
21. Dayal, S.; Clay, R.T.; Li, H.; Mazumdar, S. Paired-electron crystal: Order from frustration in the quarter-filled band. Phys. Rev. 2011, 83, 245106:1-245106:12.
22. Merino, J.; McKenzie, R.H. Superconductivity mediated by charge fluctuations in layered molecular crystals. Phys. Rev. Lett. 2001, 87, 237002:1-237002:4.
23. Cano-Cortes, L.; Merino, J.; Fratini, S. Quantum critical behavior of electrons at the edge of charge order. Phys. Rev. Lett. 2010, 105, 036405:1-036405:4.
24. Takahashi, T.; Nogami, Y.; Yakushi, K. Charge ordering in organic conductors. J. Phys. Soc. Jpn. 2006, 75, 051008:1-051008:17.
25. Seo, H.; Merino, J.; Yoshioka, H.; Ogata, M. Theoretical aspects of charge ordering in molecular conductors. J. Phys. Soc. Jpn. 2006, 75, 051009:1-051009:20.
26. Dressel, M.; Drichko, N. Optical properties of two-dimensional organic conductors: Signatures of charge ordering and correlation effects. Chem. Rev. 2004, 104, 5689-5715.
27. Dressel, M. Quantum criticality in organic conductors? Fermi liquid versus non-Fermi-liquid behavior. J. Phys. Condens. Matter 2011, 23, 293201:1-293201:21.
28. Nad, F.; Monceau, P. Dielectric response of the charge ordered state in the quasi-onedimensional conductors. J. Phys. Soc. Jpn. 2006, 75, 051005:1-051005:12.
29. 4) to a charge-ordering transition. Phys. Rev. Lett. 2003, 90, 167002:1-167002:4.
30. 4, Rb, Tl). Phys. Rev. 2006, 74, 235121:1-235121:11.
31. Kaiser, S.; Dressel, M.; Sun, Y.; Greco, A.; Schlueter, J.A.; Gard, G.L.; Drichko, N. Bandwidth tuning triggers interplay of charge order and superconductivity in two-dimensional organic materials. Phys. Rev. Lett. 2010, 105, 206402:1-206402:4.
32. 6. J. Phys. Soc. Jpn. 2008, 77, 024714:1-024714:8.
33. 6. Phys. Rev. 2009, 80, 092508:1-092508:4.
34. Girlando, A.; Masino, M.; Kaiser, S.; Sun, Y.; Drichiko, N.; Dressel, M.; Mori, H. Spectroscopic characterization of charge order fluctuations in BEDT-TTF metals and superconductors. Phys. Status Solidi 2012, 249, 953-956.
35. Kobayashi, A.; Katayama, S.; Suzumura, Y. Superconductivity in charge ordered metal for quasi-two-dimensional organic conductor. J. Phys. Soc. Jpn. 2005, 74, 2897-2900.
36. Pouget, J.-P. Bond and charge ordering in low-dimensional organic conductors. Physica B 2012, 407, 1762-1770.
37. Pouget, J.-P.; Foury-Leylekian, P.; Alemany, P.; Canadell, E. Charge ordering in low dimensional organic conductors: Structural aspects. Phys. Status Solidi 2012, 249, 937-942.
38. 2. Phys. Rev. 2001, 63, 054301:1-054301:6.
39. 2. Phys. Rev. 2002, 66, 235102:1-235102:5.
40. Merino, J.; Greco, A.; McKenzie, R.H.; Calandra, M. Dynamical properties of a strongly correlated model for quarter-filled layered organic molecular crystals. Phys. Rev. 2003, 68, 245121:1-245121:15.
41. Seo, H.; Tsutsumi, K.; Ogata, M.; Merino, J. Charge fluctuation in geometrically frustrated charge ordering system. J. Phys. Soc. Jpn. 2006, 75, 114707:1-114707:8.
42. 8. Spectrochim. Acta 1987, 43A, 323-329.
43. Kozlov, M.E.; Pokhondnia, K.I.; Yurchenko, A.A. Electron molecular vibration coupling in vibrational spectra of BEDT-TTF based radical cation salts. Spectrochim. Acta 1989, 45A, 437-444.
44. Eldridge, J.E.; Homes, C.C.; Williams, J.M.; Kini, A.M.; Wang, H.H. The assignment of the normal modes of the BEDT-TTF electron-donor molecule using the infrared and Raman spectra of several isotopic analogs. Spectrochim. Acta 1995, 51A, 947-960.
45. Wang, H.H.; Ferraro, J.R.; Williams, J.M.; Geiser, U.; Schlueter, J.A. Rapid Raman spectroscopic determination of the stoichiometry of microscopic quantities of BEDT-TTF-based organic conducors and superconductors. J. Chem. Soc. Chem. Commun. 1994, 1893-1894, doi:10.1039/C39940001893.
46. Yamamoto, T.; Uruichi, M.; Yamamoto, K.; Yakushi, K.; Kawamoto, A.; Taniguchi, H. Examination of the charge-sensitive vibrational modes in bis(ethylenedithio)tetrathiafulvalene. J. Phys. Chem. 2005, 109, 15226-15235.
47. Although frequency is proportional to the square root of force constant, the frequency practically linearly depends upon the force constant in a narrow frequency range, Δω = ω(0)-ω(1).
48. Rice, M.J.; Lipari, N.O.; Strassler, S. Dimerized organic linear-chain conductors and the unambiguous experimental determination of electron-molecular-vibration coupling constants. Phys. Rev. Lett. 1977, 21, 1357-1362.
49. Rice, M.J. Towards the experimental determiation of the fundamental microscopic parameters of organic ion-radical compounds. Solid State Commun. 1979, 31, 93-98.
50. Girlando, A.; Bozio, R.; Pecile, C.; Torrance, J.B. Discovery of vibronic effects in the Raman spectra of mixed-stack charge-transfer crystals. Phys. Rev. 1982, 26, 2306-2309.
51. Painelli, A.; Girlando, A. Electron-molecular vibration (e-mv) coupling in charge-transfer compounds and its consequences on the optical spectra: A theoretical framework. J. Chem. Phys. 1986, 84, 5655-5671.
52. Yamamoto, K.; Yakushi, K. Electron-molecular vibration coupling effect on the Raman spectrum of organic charge transfer salts. J. Phys. (France) 2004, 114, 153-155.
53. + electron-molecular vibration coupling constants through optical microreflectance. Phys. Rev. 1998, 58, 9460-9467.
54. Yartsev, V.M.; Graja, A. Electron-intramolecular vibration coupling in charge-transfer salts studied by infrared spectroscopy. Int. J. Mod. Phys. 1998, 12, 1643-1672.
55. 1-x: Optical studies of localized charge excitations. Phys. Rev. 2007, 76, 165113:1-165113:12.
56. Girlando, A. Charge sensitive vibrations and electron-molecular vibration coupling in bis(ethylenethio)-thetrathiafulvalene (BEDT-TTF). J. Phys. Chem. 2011, 115, 19371-19378.
57. 2. J. Phys. Soc. Jpn. 2004, 73, 2326-2332.
58. 2]. J. Phys. Soc. Jpn. 2009, 78, 044701:1-044701:10.
59. Kubo, R. A stochastic theory of line shape. Adv. Chem. Phys. 1969, 15, 101-127.
60. Sue, J.; Yan, Y.J.; Mukamel, S. Raman excitation profiles of polyatomic molecules in condensed phases. A stochastic theory. J. Chem. Phys. 1986, 85, 462-474.
61. Uruichi, M.; Yakushi, K.; Yamamoto, H.M.; Kato, R. Infrared and Raman studies of the charge-ordering phase transition at ~170 K in the quarter-filled organic conductor, β″-(ET) (TCNQ). J. Phys. Soc. Jpn. 2006, 75, 074720:1-074720:10.
62. Yamamoto, H.M.; Hagiwara, M.; Kato, R. New phase of (BEDT-TTF)(TCNQ). Synth. Metal. 2003, 133, 449-451.
63. Nogami, Y. Okayama University, Private communication, 2009.
64. Yamamoto, H.M.; Tajima, N.; Hagiwara, M.; Kato, R.; Yamaura, J.I. Strange electric magnetic behaviour of new (BEDT-TTF)(TCNQ). Synth. Metal. 2003, 135, 623-624.
65. Yasuzuka, S.; Terakura, C.; Terashima, T.; Yakabe, T.; Terai, Y.; Yamamoto, H.M.; Kato, R.; Uji, S. Fermi surface and resistance anomalies in ET-TCNQ. Synth. Metal. 2003, 135, 647-648.
66. Yasuzuka, S.; Graf, D.; Choi, E.S.; Brooks, J.S.; Terashima, T.; Konoike, T.; Enomoto, K.; Nishimura, M.; Yamamoto, H.M.; Kato, R.; et al. Pressure-induced Fermi surface change in quasi-one-dimensional conductor β″-(ET)(TCNQ). J. Phys. IV Fr. 2004, 114, 157-158.
67. Yasuzuka, S.; Uji, S.; Enomoto, K.; Konoike, T.; Nishimura, M.; Terashima, T.; Graf, D.; Choi, E.S.; Brooks, J.S.; Yamamoto, H.M.; et al. Pressure effect on fermi surface in β″-(ET)(TCNQ). Synth. Metal. 2005, 152, 437-440.
68. Kimata, M.; Ohta, H.; Koyama, K.; Oshima, Y.; Motokawa, M.; Yamamoto, H.M.; Kato, R. Development of the high field magneto-optical measurement system with a rotational cavity for the study of organic conductors. Int. J. Mod. Phys. 2004, 18, 3803-3806.
69. Kimata, M.; Oshima, Y.; Ohta, H.; Koyama, K.; Motokawa, M.; Yamamoto, H.M.; Kato, R. Magnetooptical measurements of β″-(BEDT-TTF)(TCNQ). Physica B 2004, 346, 382-386.
70. Yakushi, K.; Uruichi, M.; Yamamoto, H.M.; Kato, R. Dynamical fluctuation of the site-charge density in metallic β″-(BEDT-TTF)(TCNQ). J. Phys. IV Fr. 2004, 114, 149-151.
71. Drichko, N.; Kaiser, S.; Sun, Y.; Clauss, C.; Dressel, M.; Mori, H.; Schlueter, J.; Zhyliaeva, E.I.; Torunova, S.A.; Lyubovskaya, R.N. Evidence for charge order in organic superconductors obtained by vibrational spectroscopy. Physica B 2009, 404, 490-493.
72. 4 studied by vibrational spectroscopy. Phys. Rev. 2002, 65, 085110:1-085110:8.
73. There is another incoherent optical excitation at ~U with very weak intensity, which corresponds to the optical transition from the lower Hubbard to the upper Hubbard band.
74. Merino, J. Nonlocal Coulomb Correlation in metals close to a charge order insulator transition. Phys. Rev. Lett. 2007, 99, 036404:1-036404:4.
75. Kondo, R.; Higa, M.; Kagoshima, S.; Hoshino, H.; Mori, T.; Mori, H. Electrical and structural properties of θ-type BEDT-TTF organic conductors under uniaxial strain. J. Phys. Soc. Jpn. 2006, 75, 044716:1-044716:7.
76. 2X: The effect of the fermi surface nesting and the distant electron-electron interactions. J. Phys. Soc. Jpn. 2006, 75, 114716:1-114716:14.
77. Hotta, C. Classification of quasi-two dimensional organic conductors based on a new minimal model. J. Phys. Soc. Jpn. 2003, 72, 840-853.
78. Watanabe, H.; Ogata, M. Novel charge order and superconductivity in two-dimensional frustrated lattice at quarter filling. J. Phys. Soc. Jpn. 2006, 75, 063702:1-063702:4.
79. Mori, H.; Tanaka, S.; Mori, T. Systematic study of the electronic state of θ-type BEDT-TTF organic conductors by changing electronic correlation. Phys. Rev. 1998, 57, 12023-12029.
80. 1-x (x < 0.02). Chem. Lett. 1986, 789-792.
81. 4, [M' = Co, Zn]. Bull. Chem. Soc. Jpn. 1998, 71, 797-806.
82. 2. Bull Chem. Soc. Jpn. 1995, 68, 2233-2244.
83. 2P is interpreted as the Fermi resonance [72].
84. 4 at 90 K. J. Phys. Soc. Jpn. 2004, 73, 116-122.
85. 4 studied by vibrational spectroscopy. Phys. Rev. 2004, 69, 085114:1-085114:11.
86. 4 (MM' = RbCo, RbZn, CsZn) by reflection spectroscopy. Phys. Rev. 2000, 62, 9378-9385.
87. 2X. J. Phys. Soc. Jpn. 2008, 77, 034708:1-034708:9.
88. 4. Phys. Rev. Lett. 2004, 93, 216405:1-216405:4.
89. 4: Competition of different ground states. Synth. Metal. 1999, 103, 1898-1899.
90. Kanoda, K.; Ohnou, K.; Kodama, M.; Miyagawa, K.; Itou, T.; Hiraki, K. Charge ordering and frustration in organic conductors. J. Phys. IV Fr. 2005, 131, 21-26.
91. 4. Synth. Metal. 2003, 135, 665-666.
92. Nogami, Y.; Hanasaki, N.; Watanabe, M.; Yamamoto, K.; Ito, T.; Ikeda, N.; Ohsumi, H.; Tokawa, H.; Noda, Y.; Terasaki, I.; et al. Charge order competition leading to nonlinearity in organic thyristor family. J. Phys. Soc. Jpn. 2010, 79, doi:10.1143/JPSJ.79.044606.
93. 2 band with the aid of isotope shift is given in ref. [94].
94. 4. J. Phys. Soc. Jpn. 2005, 74, 2631-2639.
95. 4. J. Phys. Condens. Matter 2001, 13, 5463-5470.
96. 2X. Phys. Rev. 2008, 78, 035113:1-035113:9.
97. 3A.[46].
98. Mori, T. Non-Stripe charge order in the θ-phase organic conductors. J. Phys. Soc. Jpn. 2003, 72, 1469-1475.
99. Mori, T. Estimation of off-site coulomb integrals and phase diagrams of charge ordered states in the θ-phase organic conductor. Bull. Chem. Soc. Jpn. 2000, 73, 2243-2253.
100. 4. J. Phys. Soc. Jpn. 1999, 68, 2654-2663.
101. 4. J. Phys. Soc. Jpn. 2008, 77, 065004:1-065004:2.
102. 4. J. Phys. Soc. Jpn. 2004, 73, 3364-3369.
103. Sawano, F.; Terasaki, I.; Mori, H.; Mori, T.; Watanabe, M.; Ikeda, N.; Nogami, Y.; Noda, Y. An organic thyristor. Nature 2005, 437, 522-524.
104. 4. Phys. Rev. 2008, 77, 115113:1-115113:10.
105. 4 at low temperature. J. Phys. Condens. Matter 2008, 20, 485211:1-485211:6.
106. 2X. Phys. Rev. Lett. 2007, 98, 206405:1-206405:4.
107. 3; Transport property. Solid State Commun. 1987, 64, 1279-1284.
108. 3. Phys. Rev. 2007, 75, 054509:1-054509:13.
109. The symmetry of 3a × 3c superlattice has not been clarified.
110. 4. Synth. Metal. 2003, 135, 701-702.
111. 3. Phys. Rev. 2003, 67, 224105:1-224105:11.
112. 3 observed by optical spectroscopy. Phys. Rev. Lett. 2005, 95, 227801:1-227801:4.
113. x, (x < 0.02). Chem. Lett. 1986, 2017-2020.
114. 3: Estimation of band parameters. J. Phys. Soc. Jpn. 1988, 57, 3239-3247.
115. ACS. Molecular Conductors: Thematic Issue (Special issue). ACS Publication: Washington, DC, USA, 2004; pp. 4887-5781.
116. Mori, T. Structural genealogy of BEDT-TTF-based organic conductors I. Parallel molecules: β and β″ phases. Bull. Chem. Soc. Jpn. 1998, 71, 2509-2526.
117. Mori, T. Structural genealogy of BEDT-TTF-based organic conductors II. Inclined molecules: θ-and α-, and κ-phases. Bull. Chem. Soc. Jpn. 1999, 72, 179-197.
118. Mori, T. Structural genealogy of BEDT-TTF-based organic conductors III. Twisted molecules: δ-and α'-phases. Bull. Chem. Soc. Jpn. 1998, 72, 2011-2027.
119. 3. Synth. Metal. 2001, 120, 1081-1082.
120. 3 and discovery of superconductivity. J. Phys. Soc. Jpn. 2002, 71, 1832-1835.
121. 3. Sci. Technol. Adv. Mater. 2009, 10, 024308:1-024308:7.
122. 3. Sci. Technol. Adv. Mater. 2009, 10, 024309:1-024309:15.
123. Iwai, S.; Yamamoto, K.; Kashiwazaki, A.; Hiramatsu, F.; Nakaya, H.; Kawakami, Y.; Yakushi, K.; Okamoto, H.; Mori, H.; Nishio, Y. Photoinduced melting of a stripe-type charge-order and metallic domain formation in a layered BEDT-TTF-based organic salt. Phys. Rev. Lett. 2007, 98, 097402:1-097402:4.
124. Yamamoto, K.; Iwai, S.; Boyko, S.; Kashiwazaki, A.; Hiramatsu, F.; Okabe, C.; Nishi, N.; Yakushi, K. Strong optical nonlinearity and its ultrafast response associated with electron ferroelectricity in an organic conductor. J. Phys. Soc. Jpn. 2008, 77, 074709:1-074709:6.
125. 3-. Mol. Cryst. Liq. Cryst. 1984, 108, 359-371.
126. 2X. J. Phys. Soc. Jpn. 1996, 65, 2158-2169.
127. Takahashi, T.; Hiraki, K.; Moroto, S.; Tajima, N.; Takano, Y.; Kubo, Y.; Satsukawa, H.; Chiba, R.; Yamamoto, H.M.; Kato, R.; et al. Charge disproportionation, everywhere! J. Phys. IV Fr. 2004, 114, 3-8.
128. 3 by synchrotron x-ray diffraction. J. Phys. Soc. Jpn. 2007, 76, 113702:1-113702:4.
129. 3. Phys. Rev. B 2012, 85, 195118:1-195118:10.
130. 3. Phys. Rev. 2010, 82, 075134:1-075134:8.
131. Yamamoto, K.; Kowalska, A.A.; Yue, Y.; Yakushi, K. Vibronic activation of molecular vibrational overtones in the infrared spectra of charge-ordered organic conductors. Phys. Rev. 2011, 84, 064306:1-064306:13.
132. Yamamoto, K.; Kowalska, A.A.; Yue, Y.; Yakushi, K. E-mv coupling of vibrational overtone in organic conductors: Relationship to optical nonlinearity and ferroelectricity. Physica B 2012, 407, 1775-1778.
133. 3. Phys. Rev. 2011, 83, 165128:1-165128:13.
134. 3. J. Phys. IV Fr. 2004, 114, 339-340.
135. 3. J. Phys. Soc. Jpn. 2009, 78, 074711:1-074711:6.
136. 2Br). Molecular Electronic and Related Materials-Control and Probe with Light; Naito, T., Ed.; Transworld Research Network: Kerala, Indian, 2010; pp. 185-201.
137. 3. App. Phys. Lett. 2010, 96, 122901:1-122901:3.
138. 4. Nature 2005, 436, 1136-1138.
139. 3. Phys. Rev. 2008, 77, 125131:1-125131:5.
140. Kawakami, Y.; Fukatsu, T.; Sakurai, Y.; Unno, H.; Itoh, H.; Iwai, S.; Sasaki, T.; Yamamoto, K.; Yakushi, K.; Yonemitsu, K. Early-State dynamics of light-matter interaction leading to the insulator-to-metal transition in a charge ordered organic crystal. Phys. Rev. Lett. 2010, 105, 246402:1-246402:4.
141. +. Synth. Metal. 1991, 42, 2013-2018.
142. 4). Bull. Chem. Soc. Jpn. 1990, 63, 2183-2190.
143. 1-x (x < 0.02). Chem. Lett. 1986, 833-836.
144. 3 under hydrostatic pressure-Discovery of a novel type of conductor J. Phys. Soc. Jpn. 2000, 69, 543-551.
145. 4 and K at low temperature: Breaking of inversion symmetry due to charge-ordering fluctuation. Physica B 2010, 405, 5153-5156.
146. 4 with M = K and Rb. Synth. Metal. 2003, 137, 1271-1272.
147. 4 studied by x-ray diffuse scattering and by first-principle calculations. Phys. Rev. 2010, 82, 134116:1-134116:14.
148. -1/e).
149. Yamamoto, T.; Yamamoto, H.M.; Kato, R.; Uruichi, M.; Yakushi, K.; Akutsu, H.; Sato-Akutsu, A.; Kawamoto, A.; Turner, S.S.; Day, P. Inhomogeneous site charges at the boundary between the insulating, superconducting, and metallic phases of β″-type bis-ethylenedithio-tetrathiafulvalene molecular charge-transfer salts. Phys. Rev. 2008, 77, 205120:1-205120:14.
150. Bangura, A.F.; Coldea, A.I.; Singleton, J.; Ardavan, A.; Akutsu-Sato, A.; Akutsu, H.; Turner, S.S.; Day, P.; Yamamoto, T.; Yakushi, K. Robust superconducting state in the low-quasiparticle-density due to proximity to a charge-ordered state. Phys. Rev. 2005, 72, 014543:1-014543:13.
151. See ref. [46] about the reason why this equation is applicable in the range of 0 ≤ ρ ≤ 0.8.
152. Although frequency is proportional to the square root of force constant, the frequency practically linearly depends upon the force constant in a narrow frequency range, Δω = ω(0)-ω(1).
153. 3 which will be shown in the next subsection.
154. Hess, L.A.; Prasad, P.N. Vibrational dephasing in organic solids: Temperature dependence of Raman active internal mode of naphthalene. J. Phys. Chem. 1980, 72, 573-579.
155. 2 is necessary including temperature dependence.
156. 3. J. Phys. Conf. Ser. 2008, 132, 012003:1-012003:7.
157. Kobayashi, A.; Katayama, S.; Suzumura, Y.; Fukuyama, H. Massless fermions in organic conductor. J. Phys. Soc. Jpn. 2007, 76, 034711:1-034711:6.
158. Ishibashi, S.; Tamura, T.; Kohyama, M.; Terakura, K. Ab initio electronic-structure calculation. J. Phys. Soc. Jpn. 2006, 75, 015005:1-015005:2.
159. 3. Synth. Metal. 1997, 86, 2007-2008.
160. 4]. J. Phys. IV Fr. 2004, 114, 263-267.
161. 3 under pressure. J. Phys. Soc. Jpn. 2010, 79, 063703:1-063703:3.
162. 31, the hole numbers shown in the CO state shown in Figure 5b, c are inaccurate.
163. 3 under hydrostatic pressure at room temperature. J. Phys. Soc. Jpn. 2009, 78, 114714:1-114714:7.
164. 3. Bull. Chem. Soc. Jpn. 1987, 60, 4251-4257.
165. 3. J. Phys. Fr. 1990, 51, 869-881.
166. 3. J. Phys. I Fr. 1994, 4, 579-594.
167. 3. Physica B 2010, 405, S144-S146.
168. 3. J. Appl. Phys. 2010, 107, 103716:1-103716:5.
169. 3. Phys. Rev. Lett. 2010, 104, 206406:1-206406:4.
170. Dressel, M.; Drichko, N.; Kaiser, S. Collective charge-order excitations. Physica C 2010, 470, S589-S591.
171. 2 organic magnetic semiconductor. J. Korean Phys. Soc. 1997, 31, 95-98.
172. 2). Synth. Metal. 1987, 19, 215-220.
173. 3. J. Phys. Soc. Jpn. 1986, 55, 47-50.
174. 3. Synth. Metal. 1986, 16, 367-377.
175. 2. Synth. Metal. 1992, 103, 2102-2103.
176. 2. J. Phys. Conf. Ser. 2008, 132, 012007:1-012007:7.
177. 2. Physica B 2010, 405, S232-S236.
178. 2 studied by second-harmonic generation microscopy. J. Phys. Conf. Ser. 2008, 132, 012006:1-012006:5.
179. 2 II. Meeting Abstr. Phys. Soc. Jpn. 2012, 67, 907.
180. 3]. Phys. Rev. 1986, 34, 117-125.
181. 3 were taken from the papers reported by Wang [95] and Takenaka [112], respectively.
182. Van der Marel, D. Optical Signatures of Electron Correlations in the Cuprates. In Strong Interactions in Low Dimensions; Baeriswyl, D., Degiorgi, L., Eds.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 2004; pp. 237-276.