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Full-Text Articles in Physics
Collective Relaxation Processes In Nonchiral Nematics, Neelam Yadav, Yuri Panarin, Wanhe Jiang, Georg H. Mehl, Jagdish Vij
Collective Relaxation Processes In Nonchiral Nematics, Neelam Yadav, Yuri Panarin, Wanhe Jiang, Georg H. Mehl, Jagdish Vij
Articles
Nematic–nematic transitions in a highly polar nematic compound are studied, in thick cells in which the molecules are aligned parallel to the substrates but perpendicular to the applied electric field, using dielectric spectroscopy in the frequency range 1 Hz to 10 MHz over a wide temperature range. The studied compound displays three nematic phases under cooling from the isotropic phase: ubiquitous nematic N; high polarizability NX; and ferroelectric nematic NF. Two collective processes were observed. The dielectric strength and relaxation frequency of one of the processes P2 showed a dependence on the thickness of the cell. The process P1 is …
Calculating Van Der Waals-London Dispersion Spectra And Hamaker Coefficients Of Carbon Nanotubes In Water From Ab Initio Optical Properties, Roger H. French
Calculating Van Der Waals-London Dispersion Spectra And Hamaker Coefficients Of Carbon Nanotubes In Water From Ab Initio Optical Properties, Roger H. French
Faculty Scholarship
The van der Waals-London dispersion (vdW-Ld) spectra are calculated for the [9,3,m] metallic and [6,5,s] semiconducting single wall carbon nanotubes (SWCNTs), graphite, and graphene (a single carbon sheet of the graphite structure) using uniaxial optical properties determined from ab initio band structure calculations. The [9,3,m], exhibiting metallic optical properties in the axial direction versus semiconducting optical properties in the radial direction, highlights the strong anisotropic nature of metallic SWCNTs. Availability of both efficient ab initio local density band structure codes and sufficient computational power has allowed us to calculate the imaginary parts of the frequency dependent dielectric spectra, which are …