Pressure-induced drastic collapse of a high oxygen coordination shell in   quartz-like alpha-GeO2

doi:10.1088/1367-2630/16/2/023022

CORC > 北京大学 > 地球与空间科学学院

	Pressure-induced drastic collapse of a high oxygen coordination shell in quartz-like alpha-GeO2
	Dong, Juncai ; Zhang, Xiaoli ; Zhang, Qian ; Wu, Ye ; Wu, Xiang ; Wu, Ziyu ; Chen, Dongliang
刊名	新物理学学报
	2014
关键词	RAY-ABSORPTION SPECTROSCOPY GEO2 POLYMORPHS INDUCED AMORPHIZATION CRYSTAL-STRUCTURES FINE-STRUCTURE VITREOUS GEO2 BORON-CARBIDE MEMORY-GLASS SILICA TRANSFORMATION
DOI	10.1088/1367-2630/16/2/023022
英文摘要	With the combination of a single crystal diamond anvil cell and a polycapillary half-lens, the local structural evolution around germanium in tetrahedrally networked quartz-like alpha-GeO2 has been investigated using extended x-ray absorption fine structure spectroscopy of up to 14 GPa by multiple-scattering analysis method. While the first shell Ge-O bond distances show a slight contraction with increasing pressure, the third shell Ge-O bond distances are found to decrease dramatically. The sluggish lengthening of the first shell Ge-O bond distances, initiated by coordination increase from fourfold to sixfold, occurs in the 7-14 GPa range just when the third shell Ge-O bond distances fall in the region of the second shell Ge-Ge bond distances. Moreover, these features are accompanied by the closing of intertetrahedral Ge-O-Ge angles and the opening of two intratetrahedral O-Ge-O angles, whose topological configuration surprisingly exhibits a helical chirality along the c axis that is opposite to the double helices of the corner-linked GeO4 tetrahedra. These results suggest that the high-pressure phase transitions in quartz and quartz-like materials could be associated with a structural instability that is driven by the drastic collapse of the next-nearest-neighbour anion shell, which is consistent with the emergence of high-symmetry anion sublattice. Our findings provide crucial insights into the densification mechanisms of quartz-like oxides, which would have broad implications for our understanding of the metastability of various post-quartz crystalline phases and pressure-induced amorphization.; Physics, Multidisciplinary; SCI(E); 0; ARTICLE; xiang.wu@pku.edu.cn; wuzy@ihep.ac.cn; chendl@ihep.ac.cn; 16
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/216505]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Dong, Juncai,Zhang, Xiaoli,Zhang, Qian,et al. Pressure-induced drastic collapse of a high oxygen coordination shell in quartz-like alpha-GeO2[J]. 新物理学学报,2014.
APA	Dong, Juncai.,Zhang, Xiaoli.,Zhang, Qian.,Wu, Ye.,Wu, Xiang.,...&Chen, Dongliang.(2014).Pressure-induced drastic collapse of a high oxygen coordination shell in quartz-like alpha-GeO2.新物理学学报.
MLA	Dong, Juncai,et al."Pressure-induced drastic collapse of a high oxygen coordination shell in quartz-like alpha-GeO2".新物理学学报 (2014).