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Prediction of a high‐density phase of SiO 2 with a high dielectric constant
Author(s) -
Ouyang Lizhi,
Ching WaiYim
Publication year - 2005
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200510029
Subject(s) - dielectric , lattice constant , condensed matter physics , materials science , density functional theory , superlattice , phase (matter) , phonon , lattice (music) , high κ dielectric , inverse , chemistry , computational chemistry , optics , physics , optoelectronics , diffraction , geometry , quantum mechanics , mathematics , acoustics
We have studied a cubic phase of SiO 2 with an inverse‐Ag 2 O‐type structure by first‐principles calculations based on density functional theory. The electronic structure, dielectric, mechanical, and thermodynamic properties of this cubic phase are studied in detail. Our calculations show that this cubic phase composed of corner‐shared SiO 4 units has a density of 3.6–3.7 g/cm, higher than any known tetrahedrally‐coordinated SiO 2 phases (cf. Devine et al. [1]). It also has high optical and static dielectric constants of 3.34 and 9.73, respectively. Moreover, its lattice constant differs by only 1–2% from Si(100) surfaces, making it a suitable candidate for a defect free Si/SiO 2 superlattice. The calculated phonon dispersion demonstrates that the structure is at least locally stable. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)