Diamond-like feature

Figure 16 shows the Raman spectrum of a DLC film deposited by the IBAD technique. The Raman spectra for diamond like materials provide information on the sp bonding. The characteristic features of Raman spectra of diamond like materials consist of a graphite-like (G) peak and a disorder (D) peak in the regions 1500-1550 cm and 1330-1380 cm respectively. The relative intensities of the G and D peaks can be used to indicate qualitatively the concentration of graphite crystallites of... 

Diamond-like Phases and Carbon-based Films. Raman spectra were used to characterise ion-irradiated diamond samples.296 Raman data could be used to identify features related to point defects in diamond.297 There is Raman evidence for the formation of polycrystalline diamond from graphite at high pressures and temperatures.298 Surface C-H groups on diamond nanocrystals were characterised by IR (vC-H) and ab initio calculations, e.g. the vC-H band on a C(111)1 x 1 site is at 2834 cm-1.299... 

Figure 5 shows the excess optical depth and the excess polarization over the continuum for the BN object in OMC-1 [38]. Polarization structure in the long-wavelength wing of the ice profile is apparent, including a feature at 3.47 im which matches closely the spectroscopic feature discovered in several protostars and attributed to carbonaceous material with diamond-like stracture... 

In the course of the research into the synthesis of diamond under metastable conditions, a new class of materials, diamond-hke carbon and hydrocarbon phases, have been discovered. The diamond-like hydrocarbons (aC H) are generated by the RF self-bias method, a technique derived from RF sputtering, developed by L. Holland [61,62]. The molecular ions, derived from the particular hydrocarbon used in the plasma, disintegrate upon colliding with the substrate surface resulting in the formation of diamond-like hydrocarbon films [63]. The main structural feature of diamond-like hydrocarbons is the presence of both sp - and sp -carbon. Solid-state NMR-investigations revealed that the material contains sp -carbon atoms of the form -C-H or H-C-H [6]. 

In contrast to the scarce knowledge on hardness and elastic properties of intermetallic clathrates, there is an enormous amount of data on Einstein and Debye temperatures available in the literature. The exceptional vibrational features of these cage compounds were extensively smdied in recent years and will be discussed in the frame of this work. Needless to say that DPT calculations of electron and phonon density of states, of thermoelectric properties and of elastic properties have greatly supported clathrate research. In this context attention should be drawn to a recent work of Karttunen et al. [29], who employed the Perdew-Burke-Emzerhof hybrid density functional with localized atomic basis sets composed of Gaussian-type functions, to calculate the elastic properties of 14 different types of clathrate frameworks (for elemental structures of C, Si, Ge, Sn) predicting bulk and Young s moduli comparing them with their diamond-like, dense so called ot-phases. 

In contrast with graphite and diamond with a crystalline structure that is connected with Raman lines, amorphous carbon reveals broad bands caused by the structural disorder with an unsymmetrical Raman band in the wavenumber region between 900 and 1800 cm. Its shape is formed by two more or less significant features, originating from the graphite G line at about 1580 cm" and the D line near 1350 cm Analyzing the intensity relation 1 /1, the peak position, and their FWHM, one gets information about the diamond-likeness of the films. 

Like the Peking-British-controlled Ch ao Chou Chinese networks in the Far East, Britain s Zionist financiers are a cult unto themselves, with their own family networks, cults, and language. New York s diamond market consists, at the lower levels, mainly of members of the extremist Hasidic sects resident in the area. This exotic feature of the diamond traffic achieved public notoriety after several unexplained thefts and murders occurred in the diamond trade during 1977. 

The third and fourth structures are sometimes called the zincblende and the wurtzite structures, on account of two forms of ZnS. The zinc-blende structure is also often called the diamond structure, since it is found in diamond and some other crystals. The fundamental features of both structures are similar each ion is tetrahedrally surrounded by four ions of the opposite sign, as in Fig. XXIII-3 (a). There arc a number of ways of joining such tetrahedra to form regular crystals, however. The diamond, or zincblende, lattice is the simplest of these. In the first place, tetrahedra like Fig. XXIII-3 (a), can be formed into sheets like... 

Although the silicon atom has the same outer electronic structure as carbon its chemistry shows very little resemblance to that of carbon. It is true that elementary silicon has the same crystal structure as one of the forms of carbon (diamond) and that some of its simpler compounds have formulae like those of carbon compounds, but there is seldom much similarity in chemical or physical properties. Since it is more electro-positive than carbon it forms compounds with many metals which have typical alloy structures (see the silicides, p. 789) and some of these have the same structures as the corresponding borides. In fact, silicon in many ways resembles boron more closely than carbon, though the formulae of the compounds are usually quite different. Some of these resemblances are mentioned at the beginning of the next chapter. Silicides have few properties in common with carbides but many with borides, for example, the formation of extended networks of linked Si (B) atoms, though on the other hand few silicides are actually isostructural with borides because Si is appreciably larger than B and does not form some of the polyhedral complexes which are peculiar to boron and are one of the least understood features of boron chemistry. 

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