The neutral-to-ionic phase transition in the mixed-stack charge-transfer complex tetrathiafulvalene-p-chloranil (TTF-CA) has been studied by pressure-dependent infrared spectroscopy up to p = 11 kbar and down to low temperatures, T = 10 K. By tracking the C=O antisymmetric stretching mode of CA molecules, we accurately determine the ionicity of TTF-CA in the pressure-temperature phase diagram. At any point, the TTF-CA crystal bears only a single ionicity; there is no coexistence region or an exotic high-pressure phase. Our findings shed new light on the role of electron-phonon interaction in the neutral-ionic transition.
REFERENCES
1.
N. A.
Spaldin
, S.-W.
Cheong
, and R.
Ramesh
, Phys. Today
63
(10
), 38
(2010
).2.
C.-W.
Nan
, M. I.
Bichurin
, S.
Dong
, D.
Viehland
, and G.
Srinivasan
, J. App. Phys.
103
, 031101
(2008
).3.
S. A.
Brazovskii
, The Physics of Organic Superconductors and Conductors
(Springer-Verlag
, Berlin
, 2008
).4.
S.
Horiuchi
and Y.
Tokura
, Nat. Mater.
7
, 357
(2008
).5.
P.
Lunkenheimer
, J.
Müller
, S.
Krohns
, F.
Schrettle
, A.
Loidl
, B.
Hartmann
, R.
Rommel
, M.
de Souza
, C.
Hotta
, J. A.
Schlueter
, and M.
Lang
, Nat. Mater.
11
, 755
(2012
).6.
M.
Dressel
, M.
Dumm
, T.
Knoblauch
, B.
Köhler
, B.
Salameh
, and S.
Yasin
, Adv. Condens. Matter Phys.
2012
, 398721
(2012
).7.
J. B.
Torrance
, A.
Girlando
, J. J.
Mayerle
, J. I.
Crowley
, V. Y.
Lee
, P.
Batail
, and S. J.
LaPlaca
, Phys. Rev. Lett.
47
, 1747
(1981
).8.
H.
Okamoto
, T.
Mitani
, Y.
Tokura
, S.
Koshihara
, T.
Komatsu
, Y.
Iwasa
, T.
Koda
, and G.
Saito
, Phys. Rev. B
43
, 8224
(1991
).9.
M.
Le Cointe
, M. H.
Lemée-Cailleau
, H.
Cailleau
, B.
Toudic
, L.
Toupet
, G.
Heger
, F.
Moussa
, P.
Schweiss
, K. H.
Kraft
, and N.
Karl
, Phys. Rev. B
51
, 3374
(1995
).10.
M. H.
Lemée-Cailleau
, M.
Le Cointe
, H.
Cailleau
, T.
Luty
, F.
Moussa
, J.
Roos
, D.
Brinkmann
, B.
Toudic
, C.
Ayache
, and N.
Karl
, Phys. Rev. Lett.
79
, 1690
(1997
).11.
H.
Kishida
, H.
Takamatsu
, K.
Fujinuma
, and H.
Okamoto
, Phys. Rev. B
80
, 205201
(2009
).12.
M.
Masino
, A.
Girlando
, A.
Brillante
, R. D.
Valle
, E.
Venuti
, N.
Drichko
, and M.
Dressel
, Chem. Phys.
325
, 71
(2006
).13.
A.
Girlando
, M.
Masino
, A.
Painelli
, N.
Drichko
, M.
Dressel
, A.
Brillante
, R. G.
Della Valle
, and E.
Venuti
, Phys. Rev. B
78
, 045103
(2008
).14.
A.
Nagahori
, N.
Kubota
, and C.
Itoh
, Eur. Phys. J. B
86
, 109
(2013
).15.
Y.
Tokura
, H.
Okamoto
, T.
Koda
, T.
Mitani
, and G.
Saito
, Phys. Rev. B
38
, 2215
(1988
).16.
K.
Kobayashi
, S.
Horiuchi
, R.
Kumai
, F.
Kagawa
, Y.
Murakami
, and Y.
Tokura
, Phys. Rev. Lett.
108
, 237601
(2012
).17.
G.
Giovannetti
, S.
Kumar
, A.
Stroppa
, J.
van den Brink
, and S.
Picozzi
, Phys. Rev. Lett.
103
, 266401
(2009
).18.
M.
Masino
, A.
Girlando
, and A.
Brillante
, Phys. Rev. B
76
, 064114
(2007
).19.
T.
Ishiguro
, K.
Yamaji
, and G.
Saito
, Organic Superconductors
(Springer-Verlag
, Berlin/Heidelberg/New York
, 1998
).20.
J. B.
Torrance
, J. E.
Vazquez
, J. J.
Mayerle
, and V. Y.
Lee
, Phys. Rev. Lett.
46
, 253
(1981
).21.
K.
Takaoka
, Y.
Kaneko
, H.
Okamoto
, Y.
Tokura
, T.
Koda
, T.
Mitani
, and G.
Saito
, Phys. Rev. B
36
, 3884
(1987
).22.
A.
Moreac
, A.
Girard
, and Y.
Delugeard
, J. Phys.: Condens. Matter
8
, 3569
(1996
).23.
Y.
Tokura
, H.
Okamoto
, T.
Koda
, and T.
Mitani
, Solid State Commun.
57
, 607
(1986
).24.
T.
Mitani
, Y.
Kaneko
, S.
Tanuma
, Y.
Tokura
, T.
Koda
, and G.
Saito
, Phys. Rev. B
35
, 427
(1987
).25.
H.
Matsuzaki
, H.
Takamatsu
, H.
Kishida
, and H.
Okamoto
, J. Phys. Soc. Jpn.
74
, 2925
(2005
).26.
M.
Dressel
and N.
Drichko
, Chem. Rev.
104
, 5689
(2004
).27.
N.
Drichko
, S.
Kaiser
, Y.
Sun
, C.
Clauss
, M.
Dressel
, H.
Mori
, J.
Schlueter
, E. I.
Zhyliaeva
, S. A.
Torunova
, and R. N.
Lyubovskaya
, Physica B
404
, 490
(2009
).28.
A.
Girlando
, J. Phys. Chem. C
115
, 19371
(2011
).29.
K.
Sedlmeier
, S.
Elsässer
, D.
Neubauer
, R.
Beyer
, D.
Wu
, T.
Ivek
, S.
Tomić
, J. A.
Schlueter
, and M.
Dressel
, Phys. Rev. B
86
, 245103
(2012
).30.
A.
Girlando
, F.
Marzola
, C.
Pecile
, and J. B.
Torrance
, J. Chem. Phys.
79
, 1075
(1983
).31.
M.
Masino
, A.
Girlando
, A.
Brillante
, R. D.
Valle
, and E.
Venuti
, Mater. Sci.-Poland
22
(2004
).32.
R.
Beyer
, A.
Dengl
, M.
Herter
, N.
Barišic
, T.
Ivek
, and M.
Dressel
, “Infrared optical measurements under hydrostatic pressure
” (unpublished).33.
L. N.
Demianets
, G. A.
Emelchenko
, J.
Hesse
, N.
Karl
, A. N.
Lobachev
, and H.
Maier
, Organic Crystals, Germanates, Semiconductors
(Springer
, Berlin/Heidelberg
, 1980
).34.
M.
Dressel
and G.
Grüner
, Electrodynamics of Solids: Optical Properties of Electrons in Matter
(Cambridge University Press
, Cambridge
, 2002
).35.
36.
A.
Damascelli
, K.
Schulte
, D.
van der Marel
, and A. A.
Menovsky
, Phys. Rev. B
55
, R4863
(1997
).37.
M. H.
Lemee-Cailleau
, B.
Toudic
, H.
Cailleau
, F.
Moussa
, M. L.
Cointe
, G.
Silly
, and N.
Karl
, Ferroelectrics
127
, 19
(1992
).© 2014 AIP Publishing LLC.
2014
AIP Publishing LLC
You do not currently have access to this content.