TMA-TCNQ

TMA.TCNQ.I [trimethylammonium-(7,7,8,8-tetracyano-p-quinodi-methane) iodine], a ternary salt that behaves as a bad one-dimensional metal... 

Figure 3 (a) Structure of TMA.TCNQ.I in the monoclinic C2/m symmetry as described in Refs. 24 and 27 (b) how iodine columns and zigzag TCNQ stacks are arranged in the crystal. 

One-dimensional positional disorder is often observed in low-dimensional organic conductors and especially in the case of iodine-containing materials because If columns may exhibit random longitudinal relative shifts. Such a disorder in TMA.TCNQ.I and some of its consequences have been discussed in Sections IV. A and VI.C. In the latter material the period of the one-dimensional scattering is commensurate with the host lattice, but commensurate and incommensurate diffuse reciprocal layers can also be observed simultaneously in, for example, TTT2I3+8 [176]. The structure re-... 

Figure 23 Electron microdiffraction study of TMA.TCNQ.I. Changes in superstructure reflections at about 40 K as a function of the irradiation dose. (From Ref. 190.)...

Figure 25 Electron microdiffraction diagram of plane [40T].i> of TMA.TCNQ.I taken at 2000 kV and T 105 K. The satellites (solid arrows) are visible at )fc and are accompanied by a second series of reflections at b (fine hollow arrows) with the same component in the direction [40T], (From Ref. 31.)...

Some applications of the method will be shown for the ternary salt trimethylammonium (TMA)-TCNQ-I. Tanner et al. [43] have obtained a best fit with a Drude-Lorentz dielectric function with a>p = 5290 cm-1, -y = 2560 cm"1, ec = 2.65, , is the frequency and T is the relaxation rate of the second oscillator. The average value of the frequency-dependent conductivity below 200 cm"1 should be 19 IS- cm"1. The energy gap of 0.10 to 0.14 eV, the effective quantity of electrons participating in the electric transport Ncfi = 0.67 per molecule, and the effective mass of the carriers m = 5.2 m were found from the plasma frequency. 

Figure 1 Scattering of X-rays from a (TMA-I-TCNQ) rotating single crystal at...

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