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

	Pressure-induced drastic collapse of a high oxygen coordination shell in quartz-like alpha-GeO2
	Dong JC(董俊才); Zhang XL(张晓丽); Dong, JC; Zhang, XL; Zhang, Q; Wu, Y; Wu, X; Wu, ZY; Chen, DL; Wu ZY(吴自玉)
刊名	NEW JOURNAL OF PHYSICS
	2014
卷号	16 页码:23022
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.
学科主题	Physics
收录类别	SCI
WOS记录号	WOS:000332614100002
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/225210]
专题	中国科学院高能物理研究所
推荐引用方式 GB/T 7714	Dong JC,Zhang XL,Dong, JC,et al. Pressure-induced drastic collapse of a high oxygen coordination shell in quartz-like alpha-GeO2[J]. NEW JOURNAL OF PHYSICS,2014,16:23022.
APA	董俊才.,张晓丽.,Dong, JC.,Zhang, XL.,Zhang, Q.,...&陈栋梁.(2014).Pressure-induced drastic collapse of a high oxygen coordination shell in quartz-like alpha-GeO2.NEW JOURNAL OF PHYSICS,16,23022.
MLA	董俊才,et al."Pressure-induced drastic collapse of a high oxygen coordination shell in quartz-like alpha-GeO2".NEW JOURNAL OF PHYSICS 16(2014):23022.