Browsing by Author "Li, S."

Now showing 1 - 5 of 5
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    Ferromagnetic (Mn, N)-codoped ZnO nanopillars array: Experimental and computational insights
    (American Institute of Physics, 2014-01-16) Wang, D. D.; Xing, G. Z.; Yan, F.; Yan, Y. S.; Li, S.; Jiangsu University; University of New South Wales Sydney; Harvard University; University of Alabama Tuscaloosa
    To reveal the mechanism responsible for ferromagnetism in transition metal and hole codoped oxide semiconductors, we carry out a comparative study on Mn-doped and (Mn, N)-codoped ZnO nanopillars. Compared with Mn-doped ZnO samples, (Mn, N)-codoped ZnO nanopillars exhibit an enhanced room temperature ferromagnetism. The modulation of bound magnetic polarons via Mn and N codoping corroborates the correlation between the ferromagnetism and hole carriers, which is also verified by first-principles density functional theory calculations. Our study suggests that the electronic band alteration as a result of codoping engineering plays a critical role in stabilizing the long-range magnetic orderings. (C) 2014 AIP Publishing LLC.
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    Orientation-dependent surface potential behavior in Nb-doped BiFeO3
    (American Institute of Physics, 2012-04-23) Yan, F.; Xing, G. Z.; Islam, M.; Li, S.; Lu, L.; Drexel University; University of New South Wales Sydney; National University of Singapore; University of Alabama Tuscaloosa
    Single-phase epitaxial Nb doped BiFeO3 (BFNO) films have been grown on diverse oriented-SrTiO3 substrates by pulsed laser deposition. The orientation dependent surface potential distributions arising from combination of the screen and polarization charges on the BFNO surfaces were characterized by Kelvin probe force microscopy combining with corresponding domain structures investigation using piezoresponse force microscopy. The relationship between surface potential and potential barrier was quantitatively analyzed through tuning the substrate orientation. The present study indicates that data stability and storage density can be controlled via engineering the substrate orientations. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4705405]
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    Positive magnetoresistance in ferromagnetic Nd-doped In2O3 thin films grown by pulse laser deposition
    (American Institute of Physics, 2014-05-23) Xing, G. Z.; Yi, J. B.; Yan, F.; Wu, T.; Li, S.; University of New South Wales Sydney; Harvard University; King Abdullah University of Science & Technology; University of Alabama Tuscaloosa
    We report the magnetic and magnetotransport properties of (In0.985Nd0.015)(2)O-2.89 thin films grown by pulse laser deposition. The clear magnetization hysteresis loops with the complementary magnetic domain structure reveal the intrinsic room temperature ferromagnetism in the as-prepared films. The strong sp-f exchange interaction as a result of the rare earth doping is discussed as the origin of the magnetotransport behaviours. A positive magnetoresistance (similar to 29.2%) was observed at 5K and ascribed to the strong ferromagnetic sp-f exchange interaction in (In0.985Nd0.015)(2)O-2.89 thin films due to a large Zeeman splitting in an external magnetic field of 50 KOe. (C) 2014 AIP Publishing LLC.
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    Search for Neutrinoless Double-Beta Decay with the Upgraded EXO-200 Detector
    (2018-02-15) Albert, J. B.; Anton, G.; Badhrees, I.; Barbeau, P. S.; Bayerlein, R.; Beck, D.; Belov, V.; Breidenbach, M.; Brunner, T.; Cao, G. F.; Cen, W. R.; Chambers, C.; Cleveland, B.; Coon, M.; Craycraft, A.; Cree, W.; Daniels, T.; Danilov, M.; Daugherty, S. J.; Daughhetee, J.; Davis, J.; Delaquis, S.; Mesrobian-Kabakian, A. Der; DeVoe, R.; Didberidze, T.; Dilling, J.; Dolgolenko, A.; Dolinski, M. J.; Fairbank, W. Jr.; Farine, J.; Feyzbakhsh, S.; Fierlinger, P.; Fudenberg, D.; Gornea, R.; Graham, K.; Gratta, G.; Hall, C.; Hansen, E. V.; Hoessl, J.; Hufschmidt, P.; Hughes, M.; Jamil, A.; Jewell, M. J.; Johnson, A.; Johnston, S.; Karelin, A.; Kaufman, L. J.; Koffas, T.; Kravitz, S.; Krücken, R.; Kuchenkov, A.; Kumar, K. S.; Lan, Y.; Leonard, D. S.; Li, G. S.; Li, S.; Licciardi, C.; Lin, Y. H.; MacLellan, R.; Michel, T.; Mong, B.; Moore, D.; Murray, K.; Nelson, R.; Njoya, O.; Odian, A.; Ostrovskiy, I.; Piepke, A.; Pocar, A.; Retière, F.; Rowson, P. C.; Russell, J. J.; Schmidt, S.; Schubert, A.; Sinclair, D.; Stekhanov, V.; Tarka, M.; Tolba, T.; Tsang, R.; Vogel, P.; Vuilleumier, J. -L.; Wagenpfeil, M.; Waite, A.; Walton, T.; Weber, M.; Wen, L. J.; Wichoski, U.; Wrede, G.; Yang, L.; Yen, Y. -R; Zeldovich, O. Ya.; Zettlemoyer, J.; Ziegler, T.; University of Alabama Tuscaloosa
    Results from a search for neutrinoless double-beta decay (0νββ) of 136Xe are presented using the first year of data taken with the upgraded EXO-200 detector. Relative to previous searches by EXO-200, the energy resolution of the detector has been improved to σ/E=1.23%, the electric field in the drift region has been raised by 50%, and a system to suppress radon in the volume between the cryostat and lead shielding has been implemented. In addition, analysis techniques that improve topological discrimination between 0νββ and background events have been developed. Incorporating these hardware and analysis improvements, the median 90% confidence level 0νββ half-life sensitivity after combining with the full data set acquired before the upgrade has increased twofold to 3.7×1025  yr. No statistically significant evidence for 0νββ is observed, leading to a lower limit on the 0νββ half-life of 1.8×1025  yr at the 90% confidence level.
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    Searches for double beta decay of Xe-134 with EXO-200
    (American Physical Society, 2017-11-03) Albert, J. B.; Anton, G.; Badhrees, I.; Barbeau, P. S.; Bayerlein, R.; Beck, D.; Belov, V.; Breidenbach, M.; Brunner, T.; Cao, G. F.; Cen, W. R.; Chambers, C.; Cleveland, B.; Coon, M.; Craycraft, A.; Cree, W.; Daniels, T.; Danilov, M.; Daugherty, S. J.; Daughhetee, J.; Davis, J.; Delaquis, S.; Der Mesrobian-Kabakian, A.; DeVoe, R.; Didberidze, T.; Dilling, J.; Dolgolenko, A.; Dolinski, M. J.; Fairbank, W., Jr.; Farine, J.; Feyzbakhsh, S.; Fierlinger, P.; Fudenberg, D.; Gornea, R.; Graham, K.; Gratta, G.; Hall, C.; Hoessl, J.; Hufschmidt, P.; Hughes, M.; Jamil, A.; Jewell, M. J.; Johnson, A.; Johnston, S.; Karelin, A.; Kaufman, L. J.; Koffas, T.; Kravitz, S.; Krucken, R.; Kuchenkov, A.; Kumar, K. S.; Lan, Y.; Leonard, D. S.; Li, S.; Licciardi, C.; Lin, Y. H.; MacLellan, R.; Marino, M. G.; Michel, T.; Mong, B.; Moore, D.; Murray, K.; Nelson, R.; Njoya, O.; Odian, A.; Ostrovskiy, I.; Piepke, A.; Pocar, A.; Retiere, F.; Rowson, P. C.; Russell, J. J.; Schubert, A.; Sinclair, D.; Smith, E.; Stekhanov, V.; Tarka, M.; Tolba, T.; Tsang, R.; Vogel, P.; Vuilleumier, J. -L.; Wagenpfeil, M.; Waite, A.; Walton, J.; Walton, T.; Weber, M.; Wen, L. J.; Wichoski, U.; Yang, L.; Yen, Y. -R.; Zeldovich, O. Ya.; Zettlemoyer, J.; Ziegler, T.; Indiana University System; Indiana University Bloomington; University of Erlangen Nuremberg; Carleton University; Duke University; University of North Carolina; University of North Carolina Chapel Hill; North Carolina State University; University of Illinois System; University of Illinois Urbana-Champaign; National Research Centre - Kurchatov Institute; Alikhanov Institute for Theoretical & Experimental Physics; Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; McGill University; University of British Columbia; Chinese Academy of Sciences; Institute of High Energy Physics, CAS; Colorado State University; Laurentian University; University of South Dakota; University of Alabama Tuscaloosa; Drexel University; University of Massachusetts System; University of Massachusetts Amherst; Technical University of Munich; University of Munich; University System of Maryland; University of Maryland College Park; State University of New York (SUNY) System; State University of New York (SUNY) Stony Brook; Institute for Basic Science - Korea (IBS); Yale University; California Institute of Technology; University of Bern; King Abdulaziz City for Science & Technology; Russian Academy of Sciences; Russian Academy of Science Lebedev Physical Institute; Argonne National Laboratory; Pacific Northwest National Laboratory
    Searches for double beta decay of Xe-134 were performed with EXO-200, a single-phase liquid xenon detector designed to search for neutrinoless double beta decay of Xe-136. Using an exposure of 29.6 kg center dot yr, the lower limits of T-1/2(2 nu beta beta) > 8.7 x 10(20) yr and T-1/2(0 nu beta beta) > 1.1 x 10(23) yr at 90% confidence level were derived, with corresponding half-life sensitivities of 1.2 x 10(21) yr and 1.9 x 10(23) yr. These limits exceed those in the literature for Xe-134, improving by factors of nearly 10(5) and 2 for the two antineutrino and neutrinoless modes, respectively.