Raman spectra of carbon nanowalls (CNWs) grown using dc plasma-enhanced chemical vapor deposition were analyzed. The Raman spectra of CNWs exhibited G and D bands at ∼1580 and ∼1350cm−1, respectively. It is found that the bandwidth of the G band is relatively narrow, even when the peak intensity ratio of D band to G band is significantly high. This spectral feature of CNWs is distinguished from those of typical graphitelike carbons reported so far. From the comparison of these spectral features, it is shown that CNWs are composed of small crystallites with a high degree of graphitization.

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Breit-Wigner-Fano (BWF) Raman line in DNA-wrapped single-wall carbon nanotubes (SWNTs) was investigated. For as-produced HiPco SWNT bundles, the asymmetric profile of BWF line is clearly observed with an excitation energy of 2.33eV. The asymmetric feature almost disappears in isolated HiPco SWNTs by DNA wrapping in aqueous solution. Such a significant change provides evidence that the asymmetric feature of BWF line is attributed to the bundling effect of SWNTs. In addition, the asymmetric feature of BWF line strongly appears even when the DNA-wrapped SWNTs are exposed to air. This means that the rebundling in the DNA-wrapped SWNTs can occur due to drying.

Mechanical properties of high quality tetragonal hen egg-white lysozyme single crystals which are one type of protein crystal were investigated by the indentation method. The indentation marks were clearly observed on the crystal surface and no elastic recovery of them occurred. The value of the micro-Vickers hardness in the wet condition was estimated to be about 20 MPa at room temperature. The hardness greatly depended on the amount of intracrystalline water (mobile water) contained in the crystals. The hardness increased with increasing evaporation time to air at room temperature. It reached the maximum at about 260 MPa, which is 13 times as much as that in the wet condition. The origin of such a change in hardness was explained in terms of the dislocation mechanisms in lysozyme single crystals.

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