Conductors one-dimensional

One-dimensional complexes, 6,134 One-dimensional conductors, 6,134 One-dimensional metals Krogmann salts, 6, 136 Optical isomerism cobalt ammines, 1,12 history, 1,180... 

Fig. 7.72 Pt (99 keV) Mossbauer spectrum of the one-dimensional conductor K2[Pt(CN)4] Bro.3o 3H20 at 4.2 K (source Au in platinum at 4.2 K). The solid line represents a single Lorentzian line fitted to the measured spectrum. The dashed line represents the best fit using a sum of two Lorentzian lines with an intensity ratio of 85 15 and with the isomer shifts of the spectra of K2[Pt(CN)4]-3H20 and K2[(Pt(CN)4Br2] (from [333])...

Hamada N, Sawada S, Oshiyama A (1992) New one-dimensional conductors graphitic microtubules. Phys Rev Lett 68 1579-1581... 

Polysilanes are cr-conjugated polymers composed of Si-Si skeletons and organic pendant groups. They are insulators with filled intramolecular valence bands and empty intramolecular conduction bands. However, because of strong cr conjugation, they have rather narrow band gaps of less than 4 eV [24,25] and are converted to conductors by photoexcitation or by doping electron donors or acceptors. Recently they have attracted much attention because of their potential utility as one-dimensional conductors, nonlinear optical materials, and electroluminescent materials [26-28]. 

S. Kagoshima, H. Nagasawa, and T. Sambongi, "One-Dimensional Conductors , Springer-Verlag, New York (1982)... 

The range of possibilities for semiconduction is very great, and the applications to the operation of transistors and related devices have revolutionized the electronics industry, but an extensive discussion of these topics is beyond the scope of this text.2 Note, however, that inorganic compounds are receiving intensive attention as the source of semiconductors, superconductors (page 285), and one-dimensional conductors (Chapter 16). 

Similar to (SN)t in their one-dimenston.il conductivity properties arc the stacked columnar complexes typified by [Pl(CN)j i. These square planar ions adopt a closely spaced parallel arrangement, allowing for considerable interaction among the d i orbitals of the platinum atoms. These orbitals are normally filled with electrons, so in order to get a conduction band some oxidation (removal of electrons) must take place. This may be readily accomplished by adding a little elemental chlorine or bromine to the pure tetracyanoplatinate salt to get stoichiometries such as K-.[Pt(CN)jBr0, in which the platinum has an average oxidation state of +2.3. The oxidation may also be accomplished electrolytically. as in the preparation of Rbj(Pt(CN)4J(FHF)04 (Fig. 16.8). which has a short Pt—Pi separation. The Pt—Pt distance is only 280 pm. almost as short as that (bund in platinum metal itself (277 pm) and in oxidized platinum "pop complexes (270 to 278 pm see Chapter l5).4- Cold-bronze materials of this type were discovered as early as 1842. though they have been little understood until recent times. The complexes behave not only as one-dimensional conductors, but... 

Further examples of the jeopardy involved in casually dismissing d orbitals participation are the findings of Haddon and coworkers28 that rf-orbitat participation is especially important m S4F4, which is nonplanar, and ako that it accounts for about one-half of the delocalization energy in the one-dimensional conductor (SN)4. In the latter case, the low electronegativity of the d orbitals (see Chapter 5) increases the ionicily of the S—N bond and stabilizes the structure. 

On the basis of these extensive studies, LiPt(mnt) behaves as a simple quasi-one-dimensional conductor with a mean-field-like metal—semiconductor transition due to the Peierls instability. 

S. Barisic, A. Bjelis, i. R. Cooper and B. Leontic (eds.), Quasi One-Dimensional Conductors I , Lecture Notes in... 

Barisic, S., Bjelis, A., Cooper, J. R., Leontic, B. (Eds.) Quasi One-Dimensional Conductors I, Lecture Notes in Physics 95 Springer-Verlag, New York 1979... 

Figure 2 Various scattering processes in one-dimensional conductors. The linearized electronic energy spectrum is shown around the Fermi surface (k = kF). The processes are depicted by trajectories showing the transfer of electrons in momentum space, i refers to backward (/ = 1), forward (/ = 2, 4), and umklapp (i = 3) processes.

Figure 7 Nesting of the Fermi surface of quasi-one-dimensional conductors. At high temperature (a), the thermal fluctuations hide the warping of the surface and the conductor has a one-dimensional nesting vector Q0 = 2kf. At low temperature (b), the warping is felt and there is coherent interchain tunneling with Q0 IkjA + (it b)f>.

Highly correlated quasi-one-dimensional conductors that have repulsive interactions and electronic umklapp processes will develop a Hubbard gap in the charge excitations at Tp e v 3 [Eq. (10)] provided that... 

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