Browsing by Subject "Matrices"

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    Design and software implementation of library functions for electronic circuit simulation
    (1994) Yazgan, Mustafa Nazım
    In this thesis, the software implementation of “SIMLIB” , a library of electronic circuit simulation, is described. The building blocks of a circuit simulator, namely, input parser, types of analyses, methods and matrix solvers are discussed. The algorithms and some special techniques employed in this library, as well as ways of modifying the program are explained. SIMLIB has become a good environment for the researchers to try гınd develop new ideas on circuit simulation.
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    ItemOpen Access
    Formation of silicon nanocrystals in sapphire by ion implantation and the origin of visible photoluminescence
    (AIP Publishing, 2006) Yerli, S.; Serincan, U.; Dogan, I.; Tokay, S.; Genisel, M.; Aydınlı, Atilla; Turan, R.
    Silicon nanocrystals, average sizes ranging between 3 and 7 nm, were formed in sapphire matrix by ion implantation and subsequent annealing. Evolution of the nanocrystals was detected by Raman spectroscopy and x-ray diffraction (XRD). Raman spectra display that clusters in the matrix start to form nanocrystalline structures at annealing temperatures as low as 800 degrees C in samples with high dose Si implantation. The onset temperature of crystallization increases with decreasing dose. Raman spectroscopy and XRD reveal gradual transformation of Si clusters into crystalline form. Visible photoluminescence band appears following implantation and its intensity increases with subsequent annealing process. While the center of the peak does not shift, the intensity of the peak decreases with increasing dose. The origin of the observed photoluminescence is discussed in terms of radiation induced defects in the sapphire matrix.