Surface Modifications on Charge-Transfer Complexes Using Scanning Probe Microscopy

1993 ◽  
Vol 311 ◽  
Author(s):  
Shoji Yamaguchi ◽  
Carlos A. Valenzuela ◽  
Richard S. Potember
Keyword(s):  
Phase Transition ◽  
Charge Transfer ◽  
Optical Switching ◽  
Optical Memory ◽  
Optical Microscope ◽  
High Density ◽  
Information Storage ◽  
Charge Transfer Complexes ◽  
Charge Transfer Reaction ◽  
Copper Salts

ABSTRACTWe are exploring high density information storage systems based on organometallic materials. Silver and copper salts of tetracyanoquinodimethane (TCNQ) and its derivatives exhibit an electrical and optical field induced reversible switching phenomenon. We have demonstrated a field-induced, charge-transfer reaction driven by the electric field at the STM tip when the field generated by the STM exceeds the switching threshold of the organic charge-transfer complex. The phase transition induced by the STM tip appears as nanometer-sized domains on the metal-TCNQ and derivatives surface. We also have shown this phase transition occur by means of optical laser irradiation. This paper discusses our plans to combine our research results in optical switching with the scanning near-field optical microscope (NSOM) to develop a very high density optical memory system. In order toassess the feasibility of this, we performed a series of experiments aimed at determining the limitations of information storage using this class of organic charge transfer complexes.

Organic Charge-Transfer Complexes for High Density Storage Using a Modified Scanning Tunneling Microscope

1992 ◽  
Vol 276 ◽  
Author(s):  
Shoji Yamaguchi ◽  
Carlos A. Valenzuela ◽  
Richard S. Potember
Keyword(s):  
Charge Transfer ◽  
Scanning Tunneling Microscope ◽  
Storage System ◽  
Information Storage ◽  
Scanning Tunneling ◽  
Charge Transfer Complexes ◽  
Charge Transfer Reaction ◽  
Copper Salts ◽  
Tunneling Microscope ◽  
Switching Phenomenon

ABSTRACTWe are investigating organometallic materials which exhibit a novel fieldinduced reversible switching phenomenon. Silver and copper salts of tetracyanoquinodimethane (TCNQ) and its derivatives, prepared as polycrystalline thick films and vacuum-deposited thin films, have been imaged using a scanning tunneling microscope (STM). We have recently produced images with molecular resolution of these materials. We also have demonstrated a field-induced, charge-transfer reaction driven by the electric field at the STM tip when the field generated by the STM exceeds the switching threshold of the organic charge-transfer complex. The phase transition induced by the STM tip appears as nanometer to micrometer-sized domains on the metal-TCNQ and derivatives surface. This STM-induced chemical reaction is being explored for use in a molecular-based information storage system.

Photo-induced variation of magnetism in coordination polymers with ligand-based electron transfer

2021 ◽  
Author(s):  
Yan-Lei Lu ◽  
Wen-Long Lan ◽  
Wei Shi ◽  
Qionghua Jin ◽  
Peng Cheng
Keyword(s):  
Electron Transfer ◽  
Coordination Polymers ◽  
Optical Memory ◽  
High Density ◽  
Information Storage ◽  
Memory Devices ◽  
Storage Materials ◽  
Potential Applications ◽  
Induced Variation

Photo-induced variation of magnetism from ligand-based electron transfer have been extensively studied because of their potential applications in magneto-optical memory devices, light-responsive switches, and high-density information storage materials. In this...

One-dimensionality and neutral-to-ionic transition of some mixed-stack charge-transfer complexes

2002 ◽  
Vol 12 (9) ◽  
pp. 357-360
Author(s):  
M. Buron ◽  
E. Collet ◽  
M. H. Lemée-Cailleau ◽  
H. Cailleau ◽  
T. Luty ◽  
...  
Keyword(s):  
Phase Transition ◽  
Charge Transfer ◽  
Charge Transfer Complexes ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
Giant Dielectric ◽  
Ionic Transition ◽  
The One ◽  
Ct Complexes ◽  
Dimerization Process

Mixed-stack charge-transfer (CT) complexes undergoing the neutral-ionic (N-I) phase transition are molecular materials formed of stacks where electron donor (D) and acceptor (A) molecules regularly alternate. In the N phase, the CT is low and molecules are situated on inversion centers, while in the I phase, the increase of CT is accompanied by a lattice distortion (dimerization process and symmetry breaking). The one-dimensional (1D) architecture triggers the chain multistability by stabilizing lattice-relaxed (LR)-CT excitations ...D° A° D° A° $(D^+A^-)(D^+A^-)(D^+A^-)$ Do A" D° A° D°... These 1D nano-scale objects are at the heart of the equilibrium N-I phase transition and govern the fascinating physical properties such as giant dielectric response or photo-induced phase transformations. In this contribution, the 1D character of these critical excitations will be demonstrated by direct observation using high resolution X-Ray diffraction.

Design of quantum neutral–ionic phase transition in organic charge-transfer complexes

2003 ◽  
Vol 133-134 ◽  
pp. 615-618 ◽  
Author(s):  
S. Horiuchi ◽  
R. Kumai ◽  
Y. Okimoto ◽  
Y. Tokura
Keyword(s):  
Phase Transition ◽  
Charge Transfer ◽  
Charge Transfer Complexes

Electronic phase transition of BEDT-TTF based mixed-stack charge-transfer complexes

1999 ◽  
Vol 103 (1-3) ◽  
pp. 1804-1805 ◽  
Author(s):  
T. Hasegawa ◽  
T. Akutagawa ◽  
T. Nakamura ◽  
Y. Sasou ◽  
R. Kondo ◽  
...  
Keyword(s):  
Phase Transition ◽  
Charge Transfer ◽  
Charge Transfer Complexes ◽  
Electronic Phase

NQR study of neutral–ionic phase transition and quantum paraelectric state in organic charge-transfer complexes

2008 ◽  
Vol 10 (12) ◽  
pp. 1752-1756 ◽  
Author(s):  
Fumitatsu Iwase ◽  
Kazuya Miyagawa ◽  
Kazushi Kanoda ◽  
Sachio Horiuchi ◽  
Yoshinori Tokura
Keyword(s):  
Phase Transition ◽  
Charge Transfer ◽  
Charge Transfer Complexes ◽  
Quantum Paraelectric ◽  
Paraelectric State

scholarly journals A study of the phase transition in semiconducting 1:2 tetracyanoquinodimethane charge transfer complexes with dipropylamine derivatives: X-ray structure and polarized reflection spectra

1991 ◽  
Vol 69 (11) ◽  
pp. 1804-1811 ◽  
Author(s):  
Kim D. Truong ◽  
Claude Pépin ◽  
André D. Bandrauk ◽  
Marc Drouin ◽  
André Michel ◽  
...  
Keyword(s):  
Phase Transition ◽  
Charge Transfer ◽  
Organic Semiconductors ◽  
Charge Transfer Complexes ◽  
Reflection Spectra ◽  
Disorder Transition ◽  
X Ray ◽  
First Order Phase Transition ◽  
Peierls Transition ◽  
First Order Phase

The donors dipropylamine (DPA), methyldipropylamine (MDPA), and ethyldipropylamine (EDPA) from 1:2 charge transfer complexes with the acceptor tetracyanoquinodimethane (TCNQ). All crystals in the above series are semiconductors and undergo a first-order phase transition at the temperature around 210 K as obtained from conductivity measurements. The X-ray structure of DPA–(TCNQ)2 was obtained as a function of temperature, and shows a distinct order–disorder transition in the hydrogen-bond network between donors and acceptors. Polarized reflection spectra on single crystals of these compounds were measured as a function of temperature in the frequency range from 400 to 4000 cm−1. A detailed study of the C≡N modes of TCNQ indicates this mode is strongly influenced by the transition due to it being hydrogen bonded to the donors. The reflection coefficients of the IR active Ag modes of TCNQ also undergo a sharp discontinuity at the transition temperature. These results are interpreted as due to a cooperative order–disorder and electronic spin – Peierls transition. Key words: organic semiconductors, X-ray structure, polarized reflection spectra, phase transition, cooperative order–disorder transition, spin–Peierls transition.

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