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Ion beam enhanced emission of charged particles from hot graphite AIP Conf.

Instrumentation has been devised by coupling electric field modulation spectroscopy (EFMS) with scanning tunneling microscopy (STM) that enables the investigation of electronic band structures in semiconductors with a nanometer-scale spatial resolution. Model experiments using low-temperature-grown GaAs (LT–GaAs) epifilms show that a difference as small as 0.01 eV in electronic energy gaps between the GaAs substrate and the LT–GaAs epilayers can be distinguished in the EFMS spectra, demonstrating the high energy, as well as spatial, resolution of the STM–EFMS.

Large organic molecules and carbon clusters are basic building blocks of life, but their existence in the universe has not been confirmed beyond doubt. A number of unidentified absorption features (arising in the diffuse inter-stellar medium), usually called "Diffuse Inter-stellar Bands (DIBs)", are hypothesized to be produced by large molecules. Among these, buckminsterfullerene C 60 has gained much attention as a candidate for DIB absorbers because of its high stability in space. Two DIBs at λ ∼ 9577Å and 9632Å have been reported as possible features of C + 60 . However, it is still not clear how their existence depends on their environment. We obtained high-resolution spectra of three stars in/around the Orion Nebula, to search for any correlations of the DIB strength with carrier's physical conditions, such as dust-abundance and UV radiation field. We find three DIBs at λ ∼ 9017Å, 9210Å, and 9258Å as additional C + 60 feature candidates, which could support this identification. These DIBs have asymmetric profiles similar to the longer wavelength features. However, we also find that the relative strengths of DIBs are close to unity and differ from laboratory measurements, a similar trend as noticed for the 9577/9632 DIBs.