Diamond spectroscopic properties

Other FAs can be present in natural diamonds and in other native crystals, but they give deep levels whose spectroscopic properties are not discussed in the present volume. 

There is only one known acceptor in diamond, responsible for the p-type conductivity of the lib diamonds. For some time, it was assumed that this acceptor was aluminium [49], but it has been suggested [43] and finally shown conclusively [38] that boron was indeed responsible for the p-type conductivity and the spectroscopic properties of type lib blue diamonds. Natural lib diamonds had been identified ca. 1954 (see Sect. 2.11), and synthetic lib diamonds were obtained at the beginning of the 1960s [80]. Boron is commonly introduced as a dopant in synthetic diamonds and its ionization energy ) is 370 meV [177]. The discrete acceptor spectrum of B extends approximately 70 meV below ) and is superimposed on the two- and three-phonon spectra of Cdiam- Boron acceptor absorption lines are observed at 305, 347 and 363 meV ( 2780, 2800, and 2930 cm 1) at RT, giving phonon-assisted transitions near 464 and 504meV (see [140], and references therein). 

The physical properties of diamond films largely correspond to those of the macroscopic material. The only significant differences to bulk diamond arise from surface defects and from a possible doping. The spectroscopic properties are employed to characterize the diamond films obtained, to evaluate their quality and, where applicable, to identify defects and impurities. In the following, the main attention will be directed just to those features differing from the bulk properties of diamond. Further aspects are also discussed in Section 5.4 on the physical properties of nanodiamond that shares some characteristics with the so-called ultrananocrystalline diamond in particular. 

A. B. Harker, Reactive polishing of polycrystalline diamond and measured spectroscopic properties, in Applications of Diamond Films and Related Materials, (Y. Tzeng, M. Yoshikawa, M. Murakawa, and A. Feldman, eds.), Elsevier Science Publishers, Amsterdam, pp. 223-225 (1991)... 

Smdt F, Lamarche VME, Clentsmith GKB, Cloke FGN, Tuczek F. Vibrational and electronic stmcture of the dinuclear bis(p-nitrido) vanadium(v) complex [V(N N" 2)(p-N)]2 spectroscopic properties of the M2(p-N)2 diamond core. Dalton Trans 2005 1052-1057. 

The adamantane structure is unique as it combines three annullated cyclohexane subunits in a nearly spherical overall shape and, as such, it can be regarded as a section of the diamond crystal lattice578. Due to this property, adamantane and other diamondoid molecules are popular as model compounds for synthetic and spectroscopic purposes579 780. 

Structural Studies. In a number of communications,22-26 correlations have been sought between both the spectroscopic and chemical properties of the various carbon allotropes and their structures. Thus, an electron-energy-loss spectroscopic study22 of diamond, graphite, and amorphous carbon has shown that the differences in the X-shell ionization loss spectra of the three allotropes (Figure 1) might be the basis of a technique for distinguishing... 

The optical properties of diamond films have been studied quite extensively, too. In the spectral range from about 220 to 1000 nm pure diamond does not show any absorption at aU. This transparency renders it an attractive material for spectroscopic appUcations Uke as windows or lens systems in spectrometers. 

The per chain modulus of this pol3nner is about equal to that of diamond in the [110] direction. A polyethylene fiber with the same per chain mechanical properties would have an ultimate tensile strength in excess of one million psi. The theoretical modulus calculated for a defect free polydiacetylene chain using a spectroscopic force field is within 10% of the observed modulus. This contrasts with the case for conventional polymers, where the bulk tensile modulus is typically much less than 50% of the theoretical (spectroscopic) modulus. 

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