Distinct vibrational signatures and complex phase behavior in metallic oxygenOA北大核心
Distinct vibrational signatures and complex phase behavior in metallic oxygen
Evidence for metallization in dense oxygen has been reported for over 30 years[Desgreniers et al.,J.Phys.Chem.94,1117(1990)]at a now routinely accessible 95 GPa[Shimizu et al.,Nature 393,767(1998)].However,despite the longevity of this result and the technological advances since,the nature of the metallic phase remains poorly constrained[Akahama et al.,Phys.Rev.Lett.74,4690(1995);Goncharov et al.,Phys.Rev.B 68,224108(2003);Ma,Phys.Rev.B 76,064101(2007);and Weck et al.,Phys.Rev.Lett.102,255503(2009)].In this work,through Raman spectroscopy,we report the distinct vibrational characteristics of metallic ζ-O2 from 85 to 225 GPa.In comparison with numerical simulations,we find reasonable agreement with the C2/m candidate structure up to about 150 GPa.At higher pressures,the C2/m structure is found to be unstable and incompatible with experimental observations.Alternative candidate structures,C2/c and Ci,with only two molecules in the primitive unit cell,are found to be stable and more compatible with measurements above 175 GPa,indicative of the dissociation of(O2)4 units.Further,we report and discuss a strong hysteresis and metastability with the precursory phase ε-O2.These findings will reinvigorate experimental and theoretical work into the dense oxygen system,which will have importance for oxygen-bearing chemistry,prevalent in the deep Earth,as well as fundamental physics.
Philip Dalladay-Simpson;Bartomeu Monserrat;Li Zhang;Federico Gorelli
Center for High Pressure Science Technology Advanced Research,1690 Cailun Road,Shanghai 201203,ChinaDepartment of Materials Science and Metallurgy,University of Cambridge,27 Charles Babbage Road,Cambridge CB3 OFS,United Kingdom||Cavendish Laboratory,University of Cambridge,J.J.Thomson Avenue,Cambridge CB3 OHE,United KingdomCenter for High Pressure Science Technology Advanced Research,1690 Cailun Road,Shanghai 201203,China||Istituto Nazionale di Ottica,Consiglio Nazionale delle Ricerche(CNR-INO),50125 Florence,Italy||Shanghai Advanced Research in Physical Sciences(SHARPS),Shanghai,China
《极端条件下的物质与辐射（英文）》 2024 (002)
4-11 / 8
We would like to thank Huichao Zhang,Huixin Hu,and Yuchen Yu for their assistance in the laboratory and during sam-ple loadings,as well as Eugene Gregoryanz for useful discussions.Bartomeu Monserrat acknowledges support from a UKRI Future Leaders Fellowship(Grant No.MR/V023926/1),from the Gianna Angelopoulos Programme for Science,Technology,and Innovation,and from the Winton Programme for the Physics of Sustainability.Federico Gorelli acknowledges support from the Shanghai Science and Technology Committee,China(Grant No.22JC1410300)and the Shanghai Key Laboratory of Novel Extreme Condition Materials,China(Grant No.22dz2260800).Portions of this work were per-formed on beamline ID27 at the European Synchrotron Radiation Facility(ESRF)(Proposal Nos.CH6636 and CH6300),Grenoble,France as well as preliminary investigations on beamline 15U1 at the Shanghai Synchrotron Radiation Facility(SSRF),Shanghai,People's Republic of China.We would like to thank our beamline con-tacts Mohamed Mezouar and Gaston Garbarino for their assistance during the course of the x-ray diffraction data collection.The com-putational resources were provided by the Cambridge Tier-2 sys-tem operated by the University of Cambridge Research Computing Service and funded by the UK EPSRC(Grant No.EP/P020259/1).
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