Solid-state materials

In solid state materials, single-step electron transport between dopant species is well known. For example, electron-hole recombination accounts for luminescence in some materials [H]. Multistep hopping is also well known. Models for single and multistep transport are enjoying renewed interest in tlie context of DNA electron transfer [12, 13, 14 and 15]. Indeed, tliere are strong links between tire ET literature and tire literature of hopping conductivity in polymers [16]. 

To solve the Kohn-Sham equations a number of different approaches and strategies have been proposed. One important way in which these can differ is in the choice of basis set for expanding the Kohn-Sham orbitals. In most (but not all) DPT programs for calculating the properties of molecular systems (rather than for solid-state materials) the Kohn-Sham orbitals are expressed as a linear combination of atomic-centred basis functions ... 

In this chapter we shall consider four important problems in molecular n iudelling. First, v discuss the problem of calculating free energies. We then consider continuum solve models, which enable the effects of the solvent to be incorporated into a calculation witho requiring the solvent molecules to be represented explicitly. Third, we shall consider the simi lation of chemical reactions, including the important technique of ab initio molecular dynamic Finally, we consider how to study the nature of defects in solid-state materials. 

G. I. Stegeman and W. TormeUas, E/ectrica/, Optical, and Magnetic Properties of Organic Solid State Materials, Materials Research Society, Pittsburgh, 1994, pp. 397-412. 

R. Saito, M. Fujita, G, Dresselhaus, and M. S. Dresselhaus, In Electrical, Optical and Magnetic Properties of Organic Solid State Materials, MRS Symposia Proceedings, Boston. Edited by L. Y. Chiang, A. F. Garito, and D. J. Sandman, vol, 247, p. 333, Pittsburgh, PA, Materials Research Society Press (1992),... 

The fluid mechanics origins of shock-compression science are reflected in the early literature, which builds upon fluid mechanics concepts and is more concerned with basic issues of wave propagation than solid state materials properties. Indeed, mechanical wave measurements, upon which much of shock-compression science is built, give no direct information on defects. This fluids bias has led to a situation in which there appears to be no published terse description of shock-compressed solids comparable to Kormer s for the perfect lattice. Davison and Graham described the situation as an elastic fluid approximation. A description of shock-compressed solids in terms of the benign shock paradigm might perhaps be stated as ... 

The emphasis of the present work is science and technology in the laboratory. The natural shock-compression laboratory of meteoritic impact should not be overlooked. In these environments unique solid state materials have been synthesized for the first time. Perhaps the most common features of our Earth, Moon, and other planets and moons are the craters produced by such high velocity impacts [67C01, 87A03]. 

Sehultz, P. G. Xiang, X. D. Current Opinion in Solid State Materials Science 1998, 3, 153-158. 

Solid state materials have been studied by nuclear magnetic resonance methods over 30 years. In 1953 Wilson and Pake ) carried out a line shape analysis of a partially crystalline polymer. They noted a spectrum consisting of superimposed broad and narrow lines which they ascribed to rigid crystalline and amorphous material respectively. More recently several books and large articles have reviewed the tremendous developments in this field, particularly including those of McBrierty and Douglas 2) and the Faraday Symposium (1978)3) —on which this introduction is largely based. 

This is only the beginning of a process which ultimately results in the formation of solid state hydroxides or oxides. Actually, the solution species present in neutral or alkaline solutions of transition-metal ions are relatively poorly characterized. The formation of numerous hydroxy- and oxy-bridged polynuclear species makes their investigation very difficult. However, it is clear that there is a near-continuous transition from mononuclear solution species, through polynuclear solution species to colloidal and solid state materials. By the way, the first example of a purely inorganic compound to exhibit chirality was the olated species 9.11. 

In 1968 DairOlio et al. published the first report of analogous electrosyntheses in other systems. They had observed the formation of brittle, filmlike pyrrole black on a Pt-electrode during the anodic oxidation of pyrrole in dilute sulphuric acid. Conductivity measurements carried out on the isolated solid state materials gave a value of 8 Scm . In addition, a strong ESR signal was evidence of a high number of unpaired spins. Earlier, in 1961, H. Lund had reported — in a virtually unobtainable publication — that PPy can be produced by electrochemical polymerization. 

Dronskowski, R. (2005) Computational Chemistry of Solid State Materials, Wiley-VCH Verlag GmbH, Weinheim. 

Liebich V (1995) Characterization of the chemical homogeneity of solid-state materials by che-mometric methods Further multivariate aspects. Fresenius J Anal Chem 352 420-425. 

Guerin S, Hayden BE. 2006. Physical vapor deposition method for the high-throughput synthesis of solid-state material libraries. J Comb Chem 8 66-73. 

Iron(IV), (V), and (VI) centers are also found in solid-state materials, the coordination chemistry of which is of considerable interest because unusual structures and remarkable electronic and catalytic properties are encountered [184]. Reviews of the corresponding Mossbauer properties are found in [185-187]. 

The chemistry of iron(IV) in solid-state materials and minerals is restricted to that of oxides, since other systems such as iron(IV)-halides are not stable [186]. Iron(lV) oxides are easy to handle because they are usually stable in air, but they often have a substoichiometric composition, with oxygen vacancies contributing to varying degrees. Moreover, the samples may contain different amounts of iron(lll) in addition to the intended iron(IV) oxide, a complication which may obscure the Mossbauer data [185]. Even iron(V) was found in iron(IV) oxides due to temperature-dependent charge disproportionation [188, 189]. 

Genuine iron(V) is a very rare oxidation state. In the preparation of iron oxides (and of other solid-state materials), the intended iron(V) disproportionates mostly into an iron(lll) fraction and two parts of an iron(Vl) fraction [276]. The only example of an iron(V) oxide for which the Mbssbauer parameters are known [185] is La2Li-FeOs- A low isomer shift of = —0.41 mm s was observed at room temperature with practically zero quadmpole splitting [277], which was taken as a proof that iron is accommodated in octahedral FeOg sites surrounded by six Li ions. Although repeatedly cited, it seems that the spectra have never been published, and the data must therefore be considered with care. 

Local Structure of the Eu2+ Impurity. From the experimental perspective, the doping of lanthanide ions into solid state materials can be probed by different instrumental technics such as nuclear magnetic resonance (NMR),44 extended X-ray absorption fine structure (EXAFS),45,46 or electron paramagnetic resonance (EPR),47 which instead of giving a direct clue of the local geometry offers only data that can be corroborated to it. From the theoretical point of view,... 

Roy, R. Parameters Necessary for Adequate Characterization of Solid State Materials. Phys. Today 1965,18, 71-73. 

There is great interest in developing molecular precursors for boron-nitrogen polymers and boron nitride solid state materials, and one general procedure is described in this report. Combinations of B-trichloroborazene and hexamethyldisilazane lead to formation of a gel which, upon thermolysis, gives hexagonal boron nitride. The BN has been characterized by infrared spectroscopy, x-ray powder diffraction and transmission electron microscopy. 

The analogy drawn between -stacked solids and duplex DNA has provided a useful starting point for experiments to probe and understand DNA-medi-ated CT. As with the -stacked solids, the DNA base pair array can provide an effective medium for long range CT. Mechanistically, however, the differences between DNA and these solid state materials may be even more important to consider. Duplex DNA, as a molecular -stacked structure, undergoes dynamical motion in solution. The time-dependent and sequence-dependent structures that arise serve to modulate and gate CT. Indeed in probing DNA CT as a function of sequence and sequence-dependent structure, we may better understand mechanistically how CT proceeds and how DNA CT may be utilized. 

Square-planar ds platinum complexes could perhaps be used as the chemically sensitive layer for a chemical sensor system. These complexes are robust and form colored solid-state materials that respond spectroscopically to a wide range of volatile organic compounds (VOCs) this process has been named vapochromism. The vapochromic shifts occur in the solid-state UV-vis,... 

Moser WR, Marshik-Geurts BJ, Kingsley J, Lemberger M, Willette R, Chan A, Sunstrom JE, Boye AJ (1995) The synthesis and characterization of solid state materials produced by high shear hydrodynamic cavitation. J Mater Res 10 2322-2335... 

Figure 46 Coordination of molecules or solid-state materials to the surface of a nanoparticle.

Figure 2.56 Oxidation -reduction cycle for the roughening of an Ag electrode, After R.K. Chang and B.L. Laubc in CRC Critical Reviews in Solid State Materials Science, Vol. 12, pp, 1 73, CRC Press Inc., Boca Raton, Florida (1984).

Most semi-conducting zinc compounds, such as the chalcogenides ZnS and ZnSe, are made from simple organozinc compounds and volatile sources of chalcogens, such as H2S and H2Se. Because of the enormous economic importance of these solid-state materials, these MOCVD processes are among the major consumers of organozinc compounds. 

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