Vibrational properties of hexagonal boron nitride: Inelastic X-ray scattering and ab initio calculations; ; et al in Physical Review Letters (2007), 98(9), 095503 The phonon dispersion relations of bulk hexagonal boron nitride have been determined from inelastic x-ray scattering measurements and analyzed by ab initio calculations. Experimental data and calculations ... [more ▼] The phonon dispersion relations of bulk hexagonal boron nitride have been determined from inelastic x-ray scattering measurements and analyzed by ab initio calculations. Experimental data and calculations show an outstanding agreement and reconcile the controversies raised by recent experimental data obtained by electron-energy loss spectroscopy and second-order Raman scattering. [less ▲] Detailed reference viewed: 123 (2 UL) Raman spectroscopy of single-wall boron nitride nanotubes; ; et al in Nano Letters (2006), 6(8), 1812-1816 Single-wall boron nitride nanotubes samples synthesized by laser vaporization of a hexagonal BN target under a nitrogen atmosphere are studied by UV and visible Raman spectroscopy. We show that resonant ... [more ▼] Single-wall boron nitride nanotubes samples synthesized by laser vaporization of a hexagonal BN target under a nitrogen atmosphere are studied by UV and visible Raman spectroscopy. We show that resonant conditions are necessary for investigating phonon modes of BNNTs. Raman excitation in the UV (229 nm) provides preresonant conditions, allowing the identification of the A(1) tangential mode at 1370 cm(-1). This is 5 cm(-1) higher than the E-2g mode in bulk h-BN. Ab initio calculations show that the lower frequency of bulk h-BN with respect to large diameter nanotubes and the single sheet of h-BN is related to a softening of the sp2 bonds in the bulk due to interlayer interaction. [less ▲] Detailed reference viewed: 111 (2 UL) |
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