Crystalline graphite

The measured magnetic susceptibility of multilayer buckytubes for xb S approximately half xg of graphite. This can be interpreted as follows. We recall that crystalline graphite is a semimetal with a small band overlap and a low density of carriers (10 /cm )[33, 34] the in-plane effective mass is small (rn ... 

TT-Electron materials, which are defined as those having extended Jt-electron clouds in the solid state, have various peculiar properties such as high electron mobility and chemical/biological activities. We have developed a set of techniques for synthesizing carbonaceous K-electron materials, especially crystalline graphite and carbon nanotubes, at temperatures below 1000°C. We have also revealed new types of physical or chemical interactions between Jt-electron materials and various other materials. The unique interactions found in various Jt-electron materials, especially carbon nanotubes, will lay the foundation for developing novel functional, electronic devices in the next generation. 

This chapter describes some of the recent results on the low-temperature synthesis of crystalline graphite and CNTs, referring to various characteristics relating to the 7i-electron materials, which have been found in the Yoshimura 7i-Electron Materials Project [11] of the ERATO program in Japanese... 

Whereas the electrochemical decomposition of propylene carbonate (PC) on graphite electrodes at potentials between 1 and 0.8 V vs. Li/Li was already reported in 1970 [140], it took about four years to find out that this reaction is accompanied by a partially reversible electrochemical intercalation of solvated lithium ions, Li (solv)y, into the graphite host [64], In general, the intercalation of Li (and other alkali-metal) ions from electrolytes with organic donor solvents into fairly crystalline graphitic carbons quite often yields solvated (ternary) lithiated graphites, Li r(solv)yC 1 (Fig. 8) [7,24,26,65,66,141-146],... 

Depending on the precursor and the heat-treatment temperature, the carbonaceous materials discussed so far contain heteroatoms in addition to the prevailing carbon atoms. Even highly crystalline graphite is saturated with heteroatoms at dislocations in the crystallites and at the edges... 

FIG. 21. E2g and vibration modes of crystalline graphite. (Reproduced from [10].)... 

In fact, crystalline graphites usually cannot be operated in PC electrolytes, unless effective film forming electrolyte additives are used (see above) as propane gas evolution [35], creation of solvated graphite intercalation compounds (sGICs) [36], and graphite exfoliation take place. Recently [37, 38], it was found that propylene evolution is observed at graphite, while absent at lithium active metallic anodes, e.g., Sn and SnSb. 

The morphology of Prussian blue electrodeposited onto a mono-crystalline graphite surface was investigated by atomic force microscopy (ATM) and is presented in... 

Everyone knew that there are precisely three forms for the element carbon amorphous carbon, as in charcoal crystalline graphite, which is packed in hexagonal sheets and crystalline diamond, which is packed in three-dimensional tetrahedral networks. 

Recall from Section 1.4.5.1 that there are two primary types of carbon fibers polyacrylonitrile (PAN)-based and pitch-based. There are also different structural forms of these fibers, such as amorphous carbon and crystalline (graphite) fibers. Typically, PAN-based carbon fibers are 93-95% carbon, whereas graphite fibers are usually 99+%, although the terms carbon and graphite are often used interchangeably. We will not try to burden ourselves with too many distinctions here, since the point is to simply introduce the relative benefits of continuous-fiber composites over other types of composites, and not to investigate the minute differences between the various types of carbon-fiber-based composites. The interested reader is referred to the abundance of literature on carbon-fiber-reinforced composites to discern these differences. 

The types of graphitic carbon powders which primarily are applied as conductive additive belong to the family of highly crystalline graphite materials. These graphite materials show real densities of 2.24-2.27 g cm-3 (values based on the xylene density according to DIN 12 797 and DIN 51 901-X) and average interlayer distances of c/2 = 0.3354-0.3360 nm.55... 

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