2010/08/31 by Shoichiro Saito, Tomoya Ono · 7 citations
Chemistry · Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #Advanced ceramic materials synthesis #Analytical Chemistry (journal) #Bond length #Chemistry #Composite material #Compression (physics) #Cristobalite #Crystal structure #Crystallography #Glass properties and applications #High-pressure geophysics and materials #Lattice (music) #Materials science #Mineralogy #Physics #Quartz #Rutile #Stishovite #Tetrahedron #Thermodynamics #Volume (thermodynamics) #cond-mat.mtrl-sci
paper · pdf · doi:10.1143/jjap.50.021503
published in Japanese Journal of Applied Physics 50(2R), 021503 (Institute of Physics) · 15 pages, 5 figures and 2 tables
openalex publication_date 2011/02/01 · arxiv created 2011/04/12 · arxiv updated 2015/05/19 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The detailed analysis of the structural variations of three GeO 2 and SiO 2 polymorphs (α-quartz, α-cristobalite, and rutile) under compression and expansion pressure is reported. First-principles total-energy calculations reveal that the rutile structure is the most stable phase among the phases of GeO 2 , while SiO 2 preferentially forms quartz. GeO 4 tetrahedras of quartz and cristobalite GeO 2 phases at the equilibrium volume are more significantly distorted than those of SiO 2 . Moreover, in the case of quartz GeO 2 and cristobalite GeO 2 , all O–Ge–O bond angles vary when the volume of the GeO 2 bulk changes from the equilibrium point, which causes further deformation of tetrahedra. In contrast, the tilt angle formed by Si–O–Si in SiO 2 markedly changes. This flexibility of the O–Ge–O bonds reduces the stress at the Ge/GeO 2 interface due to the lattice-constant mismatch and results in the low defective interface observed in the experiments [Matsubara et al. : Appl. Phys. Lett. 93 (2008) 032104; Hosoi et al. : Appl. Phys. Lett. 94 (2009) 202112].