caa a22 4500 463221451 CHVBK 20180405153213.0 cr unu---uuuuu 170326e20070801xx s 000 0 eng 10.1007/s10853-007-1526-9 doi (NATIONALLICENCE)springer-10.1007/s10853-007-1526-9 Theoretical study of the insulating oxides and nitrides: SiO2, GeO2, Al2O3, Si3N4, and Ge3N4 [Elektronische Daten] [Cem Sevik, Ceyhun Bulutay] An extensive theoretical study is performed for wide bandgap crystalline oxides and nitrides, namely, SiO2, GeO2, Al2O3, Si3N4, and Ge3N4. Their important polymorphs are considered which are for SiO2: α-quartz, α- and β-cristobalite and stishovite, for GeO2: α-quartz, and rutile, for Al2O3: α-phase, for Si3N4 and Ge3N4: α- and β-phases. This work constitutes a comprehensive account of both electronic structure and the elastic properties of these important insulating oxides and nitrides obtained with high accuracy based on density functional theory within the local density approximation. Two different norm-conserving ab initio pseudopotentials have been tested which agree in all respects with the only exception arising for the elastic properties of rutile GeO2. The agreement with experimental values, when available, are seen to be highly satisfactory. The uniformity and the well convergence of this approach enables an unbiased assessment of important physical parameters within each material and among different insulating oxide and nitrides. The computed static electric susceptibilities are observed to display a strong correlation with their mass densities. There is a marked discrepancy between the considered oxides and nitrides with the latter having sudden increase of density of states away from the respective band edges. This is expected to give rise to excessive carrier scattering which can practically preclude bulk impact ionization process in Si3N4 and Ge3N4. Springer Science+Business Media, LLC, 2007 Sevik Cem Department of Physics and National Nanotechnology Research Center, Bilkent University, 06800, Ankara, Turkey aut Bulutay Ceyhun Department of Physics and National Nanotechnology Research Center, Bilkent University, 06800, Ankara, Turkey aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/16(2007-08-01), 6555-6565 0022-2461 42:16<6555 2007 42 10853 https://doi.org/10.1007/s10853-007-1526-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-007-1526-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sevik Cem Department of Physics and National Nanotechnology Research Center, Bilkent University, 06800, Ankara, Turkey aut NATIONALLICENCE 700 1- Bulutay Ceyhun Department of Physics and National Nanotechnology Research Center, Bilkent University, 06800, Ankara, Turkey aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/16(2007-08-01), 6555-6565 0022-2461 42:16<6555 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer