@article{MoffetRoedelKellyetal.2013,
  author    = {Moffet, R. C. and R{\"o}del, R. C. and Kelly, S. T. and Yu, X. Y. and Carroll, G. T. and Fast, J. and Zaveri, R. A. and Laskin, A. and Gilles, M. K.},
  title     = {Spectro-microscopic measurements of carbonaceous aerosol aging in Central California},
  series = {Atmospheric Chemistry and Physics},
  volume    = {13},
  journal   = {Atmospheric Chemistry and Physics},
  number    = {20},
  issn      = {1680-7324},
  doi       = {10.5194/acp-13-10445-2013},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121827},
  year      = {2013},
  abstract  = {Carbonaceous aerosols are responsible for large uncertainties in climate models, degraded visibility, and adverse health effects. The Carbonaceous Aerosols and Radiative Effects Study (CARES) was designed to study carbonaceous aerosols in the natural environment of the Central Valley, California, and learn more about their atmospheric formation and aging. This paper presents results from spectro-microscopic measurements of carbonaceous particles collected during CARES at the time of a pollution accumulation event (27-29 June 2010), when in situ measurements indicated an increase in the organic carbon content of aerosols as the Sacramento urban plume aged. Computer-controlled scanning electron microscopy coupled with an energy dispersive X-ray detector (CCSEM/EDX) and scanning transmission X-ray microscopy coupled with near-edge X-ray absorption spectroscopy (STXM/NEXAFS) were used to probe the chemical composition and morphology of individual particles. It was found that the mass of organic carbon on individual particles increased through condensation of secondary organic aerosol. STXM/NEXAFS indicated that the number fraction of homogenous organic particles lacking inorganic inclusions (greater than similar to 50 nm equivalent circular diameter) increased with plume age, as did the organic mass per particle. Comparison of the CARES spectro-microscopic dataset with a similar dataset obtained in Mexico City during the MILAGRO campaign showed that fresh particles in Mexico City contained three times as much carbon as those sampled during CARES. The number fraction of soot particles at the Mexico City urban site (ranging from 16.6 to 47.3 \%) was larger than at the CARES urban site (13.4-15.7\%), and the most aged samples from CARES contained fewer carbon-carbon double bonds. Differences between carbonaceous particles in Mexico City and California result from different sources, photochemical conditions, gas phase reactants, and secondary organic aerosol precursors. The detailed results provided by these spectro-microscopic measurements will allow for a comprehensive evaluation of aerosol process models used in climate research.},
  language  = {en}
}
@article{BareilleFortunaRoedeletal.2014,
  author    = {Bareille, C. and Fortuna, F. and R{\"o}del, T. C. and Bertran, F. and Gabay, M. and Hijano Cubelos, O. and Taleb-Ibrahimi, A. and Le F{\`e}vre, P. and Bibes, M. and Barthelemy, A. and Maroutian, T. and Lecoeur, P. and Rozenberg, M. J. and Santander-Syro, A. F.},
  title     = {Two-dimensional electron gas with six-fold symmetry at the (111) surface of KTaO3},
  series = {Scientific Reports},
  volume    = {4},
  journal   = {Scientific Reports},
  issn      = {2045-2322},
  doi       = {10.1038/srep03586},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117703},
  pages     = {3586},
  year      = {2014},
  abstract  = {Two-dimensional electron gases (2DEGs) at transition-metal oxide (TMO) interfaces, and boundary states in topological insulators, are being intensively investigated. The former system harbors superconductivity, large magneto-resistance, and ferromagnetism. In the latter, honeycomb-lattice geometry plus bulk spin-orbit interactions lead to topologically protected spin-polarized bands. 2DEGs in TMOs with a honeycomb-like structure could yield new states of matter, but they had not been experimentally realized, yet. We successfully created a 2DEG at the (111) surface of KTaO3, a strong insulator with large spin-orbit coupling. Its confined states form a network of weakly-dispersing electronic gutters with 6-fold symmetry, a topology novel to all known oxide-based 2DEGs. If those pertain to just one Ta-(111) bilayer, model calculations predict that it can be a topological metal. Our findings demonstrate that completely new electronic states, with symmetries not realized in the bulk, can be tailored in oxide surfaces, promising for TMO-based devices.},
  language  = {en}
}