Current Status and Future Challenges for Teacher Training for ESD

STEM micrographs of 99% ¹³C graphene imaged with electrons accelerated by a voltage of 100 kV. Each item in the fileset is a ZIP archive containing a single time series of consecutive frames recorded with a medium angle annular dark field detector until an ejection was observed

Electronic Structure of Carbon Nanotubes with Ultrahigh Curvature

The electronic and the vibrational structure of carbon nanotubes with ultrahigh curvature was systematically studied by resonance Raman scattering, high-resolution transmission electron microscopy (HRTEM), molecular dynamics, and ab initio DFT calculations. The ultrahigh curvature tubes were grown inside commercial HiPco tubes after filling the latter with the small but carbon-rich molecule ferrocene. TEM showed partial filling of the outer tubes with inner tubes and mobility of the latter in the electron beam. The smallest analyzed tube was of (5,0) chirality and had a DFT determined diameter of 0.406 nm and a radial breathing mode frequency of 570 cm−1. For all inner tubes which had transitions in the visible spectral range, transition energies and RBM frequencies were determined with a resonance width of only 45 meV. Experimentally determined transition energies revealed dramatic deviations up to several electronvolts compared to tight-binding calculations and a significant family spread of more than 2 eV but were in agreement with many electron contribution corrected extended tight-binding results and with results from DFT calculations

Electronic Structure of Carbon Nanotubes with Ultrahigh Curvature

The electronic and the vibrational structure of carbon nanotubes with ultrahigh curvature was systematically studied by resonance Raman scattering, high-resolution transmission electron microscopy (HRTEM), molecular dynamics, and ab initio DFT calculations. The ultrahigh curvature tubes were grown inside commercial HiPco tubes after filling the latter with the small but carbon-rich molecule ferrocene. TEM showed partial filling of the outer tubes with inner tubes and mobility of the latter in the electron beam. The smallest analyzed tube was of (5,0) chirality and had a DFT determined diameter of 0.406 nm and a radial breathing mode frequency of 570 cm−1. For all inner tubes which had transitions in the visible spectral range, transition energies and RBM frequencies were determined with a resonance width of only 45 meV. Experimentally determined transition energies revealed dramatic deviations up to several electronvolts compared to tight-binding calculations and a significant family spread of more than 2 eV but were in agreement with many electron contribution corrected extended tight-binding results and with results from DFT calculations

12C graphene, 95 kV

STEM micrographs of 99% ¹²C graphene imaged with electrons accelerated by a voltage of 95 kV. Each item in the fileset is a ZIP archive containing a single time series of consecutive frames recorded with a medium angle annular dark field detector until an ejection was observed.<br

12C graphene, 85 kV

STEM micrographs of 99% ¹²C graphene imaged with electrons accelerated by a voltage of 85 kV. Each item in the fileset is a ZIP archive containing a single time series of consecutive frames recorded with a medium angle annular dark field detector until an ejection was observed.<br

13C graphene, 90 kV

STEM micrographs of 99% ¹³C graphene imaged with electrons accelerated by a voltage of 90 kV. Each item in the fileset is a ZIP archive containing a single time series of consecutive frames recorded with a medium angle annular dark field detector until an ejection was observed

12C graphene, 90 kV

STEM micrographs of 99% ¹²C graphene imaged with electrons accelerated by a voltage of 90 kV. Each item in the fileset is a ZIP archive containing a single time series of consecutive frames recorded with a medium angle annular dark field detector until an ejection was observed.<br

12C graphene, 100 kV

STEM micrographs of 99% ¹²C graphene imaged with electrons accelerated by a voltage of 100 kV. Each item in the fileset is a ZIP archive containing a single time series of consecutive frames recorded with a medium angle annular dark field detector until an ejection was observed.<br