We review recent progress in studying silicate, carbonate, and metallic liquids of geological and geophysical importance at high pressure and temperature, using the large-volume high-pressure devices at the third-gene...We review recent progress in studying silicate, carbonate, and metallic liquids of geological and geophysical importance at high pressure and temperature, using the large-volume high-pressure devices at the third-generation synchrotron facility of the Advanced Photon Source, Argonne National Laboratory. These integrated high-pressure facilities now offer a unique combination of experimental techniques that allow researchers to investigate structure, density, elasticity, viscosity, and interfacial tension of geo-liquids under high pressure, in a coordinated and systematic fashion. Experimental techniques are described, along with scientific highlights. Future developments are also discussed.展开更多
The lower mantle makes up more than a half of our planet’s volume. Mineralogical and petrological experiments on realistic bulk compositions under high pressure–temperature (P–T) conditions are essential for unders...The lower mantle makes up more than a half of our planet’s volume. Mineralogical and petrological experiments on realistic bulk compositions under high pressure–temperature (P–T) conditions are essential for understanding deep mantle processes. Such high P–T experiments are commonly conducted in a laser-heated diamond anvil cell, producing a multiphase assemblage consisting of 100 nm to submicron crystallite grains. The structures of these lower mantle phases often cannot be preserved upon pressure quenching;thus, in situ characterization is needed. The X-ray diffraction (XRD) pattern of such a multiphase assemblage usually displays a mixture of diffraction spots and rings as a result of the coarse grain size relative to the small X-ray beam size (3–5 lm) available at the synchrotron facilities. Severe peak overlapping from multiple phases renders the powder XRD method inadequate for indexing new phases and minor phases. Consequently, structure determination of new phases in a high P–T multiphase assemblage has been extremely difficult using conventional XRD techniques. Our recent development of multigrain XRD in high-pressure research has enabled the indexation of hundreds of individual crystallite grains simultaneously through the determination of crystallographic orientations for these individual grains. Once indexation is achieved, each grain can be treated as a single crystal. The combined crystallographic information from individual grains can be used to determine the crystal structures of new phases and minor phases simultaneously in a multiphase system. With this new development, we have opened up a new area of crystallography under the high P–T conditions of the deep lower mantle. This paper explains key challenges in studying multiphase systems and demonstrates the unique capabilities of high-pressure multigrain XRD through successful examples of its applications.展开更多
Diamond anvil cell techniques have been improved to allow access to the multimegabar ultrahigh-pressure region for exploring novel phenomena in condensedmatter.However,the onlyway to determine crystal structures of ma...Diamond anvil cell techniques have been improved to allow access to the multimegabar ultrahigh-pressure region for exploring novel phenomena in condensedmatter.However,the onlyway to determine crystal structures of materials above 100 GPa,namely,X-ray diffraction(XRD),especially for lowZ materials,remains nontrivial in the ultrahigh-pressure region,even with the availability of brilliant synchrotron X-ray sources.In thiswork,we performa systematic study,choosing hydrogen(the lowest X-ray scatterer)as the subject,to understand how to better perform XRD measurements of low Z materials at multimegabar pressures.The techniques that we have developed have been proved to be effective in measuring the crystal structure of solid hydrogen up to 254GPa at room temperature[C.Ji et al.,Nature 573,558–562(2019)].Wepresent our discoveries and experienceswith regard to several aspects of thiswork,namely,diamond anvil selection,sample configuration for ultrahigh-pressure XRDstudies,XRDdiagnostics for low Z materials,and related issues in data interpretation and pressure calibration.Webelieve that these methods can be readily extended to other low Z materials and can pave the way for studying the crystal structure of hydrogen at higher pressures,eventually testing structural models of metallic hydrogen.展开更多
Recently,a series of novel compounds Ba3MX5(M=Fe,Ti,V;X=Se,Te)with hexagonal crystal structures composed of quasi-1-dimensional(1D)magnetic chains has been synthesized by our research team using high-pressure and high...Recently,a series of novel compounds Ba3MX5(M=Fe,Ti,V;X=Se,Te)with hexagonal crystal structures composed of quasi-1-dimensional(1D)magnetic chains has been synthesized by our research team using high-pressure and high-temperature methods.The initial hexagonal phases persist to the maximum achievable pressure,while spin configurations and magnetic interactions may change dramatically as a result of considerable reductions in interchain separations upon pressurization.These compounds therefore offer unique possibilities for studying the evolution of intrinsic electronic structures in quasi-1D magnetic systems.Here we present a systematic investigation of Ba9Fe3Te15,in which the interchain separations between trimerized 1D chains(~10.2Å)can be effectively modulated by external high pressure.The crystal structure especially along the 1D chains exhibits an abnormal expansion at^GPa,which accompanies trimerization entangled anomalous mixed-high-low spin transition.An insulator-metal transition has been observed under high pressure as a result of charge-transfer gap closing.Pressure-induced superconductivity emerges at 26 GPa,where the charge-transfer gap fully closes,3D electronic configuration forms and local spin fully collapses.展开更多
Plastic strain-induced phase transformations(PTs)and chemical reactions under high pressure are broadly spread in modern technologies,friction and wear,geophysics,and astrogeology.However,because of very heterogeneous...Plastic strain-induced phase transformations(PTs)and chemical reactions under high pressure are broadly spread in modern technologies,friction and wear,geophysics,and astrogeology.However,because of very heterogeneous fields of plastic strain Ep and stressσtensors and volume fraction c of phases in a sample compressed in a diamond anvil cell(DAC)and impossibility ofmeasurements ofσand Ep,there are no strict kinetic equations for them.Here,we develop a kineticmodel,finite element method(FEM)approach,and combined FEM-experimental approaches to determine all fields in strongly plastically predeformed Zr compressed in DAC,and specific kinetic equation forα-ωPT consistent with experimental data for the entire sample.Since all fields in the sample are very heterogeneous,data are obtained for numerous complex 7D paths in the space of 3 components of the plastic strain tensor and 4 components of the stress tensor.Kinetic equation depends on accumulated plastic strain(instead of time)and pressure and is independent of plastic strain and deviatoric stress tensors,i.e.,it can be applied for various above processes.Our results initiate kinetic studies of strain-induced PTs and provide efforts toward more comprehensive understanding of material behavior in extreme conditions.展开更多
Glassy carbon(GC)is a type of non-graphitizing disordered carbon material at ambient pressure and high temperatures,which has been widely used due to its excellent mechanical properties.Here we report the changes in t...Glassy carbon(GC)is a type of non-graphitizing disordered carbon material at ambient pressure and high temperatures,which has been widely used due to its excellent mechanical properties.Here we report the changes in the microstructure and mechanical properties of GC treated at high pressures(up to 5 GPa)and high temperatures.The formation of intermediate sp2-sp3 phases is identified at moderate treatment temperatures before the complete graphitization of GC,by analyzing synchrotron X-ray diffraction,Raman spectra,and transmission electron microscopy images.The intermediate metastable carbon materials exhibit superior mechanical properties with hardness reaching up to 10 GPa and compressive strength reaching as high as 2.5 GPa,nearly doubling those of raw GC,and improving elasticity and thermal stability.The synthesis pressure used in this study can be achieved in the industry on a commercial scale,enabling the scalable synthesis of this type of strong,hard,and elastic carbon materials.展开更多
基金support from the National Science Foundation (Nos. EAR-0001088, 0711057, and 1214376)Guoyin Shen acknowledges support from the DOE (Nos. DE-NA0001974 and DE-FG02-99ER45775)+5 种基金COMPRES for the support in developing the PEP system. Portions of this work were performed at GeoS oilE nviroC ARS (Sector 13), Advanced Photon Source (APS), Argonne National LaboratoryGeo Soil Enviro CARS is supported by the National Science Foundation-Earth Sciences (No. EAR-1128799)Department of Energy-Geo Sciences (No. DE-FG02-94ER14466)HPCAT operations are supported by DOE-NNSA under Award (Nos. DE-NA0001974)DOE-BES under Award (No. DE-FG02-99ER45775), with partial instrumentation funding by NSFUse of the Advanced Photon Source was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract (No. DE-AC02-06CH11357)
文摘We review recent progress in studying silicate, carbonate, and metallic liquids of geological and geophysical importance at high pressure and temperature, using the large-volume high-pressure devices at the third-generation synchrotron facility of the Advanced Photon Source, Argonne National Laboratory. These integrated high-pressure facilities now offer a unique combination of experimental techniques that allow researchers to investigate structure, density, elasticity, viscosity, and interfacial tension of geo-liquids under high pressure, in a coordinated and systematic fashion. Experimental techniques are described, along with scientific highlights. Future developments are also discussed.
基金This work was supported by the National Natural Science Foundation of China (41574080 and U1530402).
文摘The lower mantle makes up more than a half of our planet’s volume. Mineralogical and petrological experiments on realistic bulk compositions under high pressure–temperature (P–T) conditions are essential for understanding deep mantle processes. Such high P–T experiments are commonly conducted in a laser-heated diamond anvil cell, producing a multiphase assemblage consisting of 100 nm to submicron crystallite grains. The structures of these lower mantle phases often cannot be preserved upon pressure quenching;thus, in situ characterization is needed. The X-ray diffraction (XRD) pattern of such a multiphase assemblage usually displays a mixture of diffraction spots and rings as a result of the coarse grain size relative to the small X-ray beam size (3–5 lm) available at the synchrotron facilities. Severe peak overlapping from multiple phases renders the powder XRD method inadequate for indexing new phases and minor phases. Consequently, structure determination of new phases in a high P–T multiphase assemblage has been extremely difficult using conventional XRD techniques. Our recent development of multigrain XRD in high-pressure research has enabled the indexation of hundreds of individual crystallite grains simultaneously through the determination of crystallographic orientations for these individual grains. Once indexation is achieved, each grain can be treated as a single crystal. The combined crystallographic information from individual grains can be used to determine the crystal structures of new phases and minor phases simultaneously in a multiphase system. With this new development, we have opened up a new area of crystallography under the high P–T conditions of the deep lower mantle. This paper explains key challenges in studying multiphase systems and demonstrates the unique capabilities of high-pressure multigrain XRD through successful examples of its applications.
基金This research was supported by the National Natural Science Foundation of China under Award No.U1930401the Department of Energy(DOE),Office of Basic Energy Science,Division of Materials Sciences and Engineering under Award No.DE-FG02-99ER45775
文摘Diamond anvil cell techniques have been improved to allow access to the multimegabar ultrahigh-pressure region for exploring novel phenomena in condensedmatter.However,the onlyway to determine crystal structures of materials above 100 GPa,namely,X-ray diffraction(XRD),especially for lowZ materials,remains nontrivial in the ultrahigh-pressure region,even with the availability of brilliant synchrotron X-ray sources.In thiswork,we performa systematic study,choosing hydrogen(the lowest X-ray scatterer)as the subject,to understand how to better perform XRD measurements of low Z materials at multimegabar pressures.The techniques that we have developed have been proved to be effective in measuring the crystal structure of solid hydrogen up to 254GPa at room temperature[C.Ji et al.,Nature 573,558–562(2019)].Wepresent our discoveries and experienceswith regard to several aspects of thiswork,namely,diamond anvil selection,sample configuration for ultrahigh-pressure XRDstudies,XRDdiagnostics for low Z materials,and related issues in data interpretation and pressure calibration.Webelieve that these methods can be readily extended to other low Z materials and can pave the way for studying the crystal structure of hydrogen at higher pressures,eventually testing structural models of metallic hydrogen.
基金Supported by the National Natural Science Foundation of China(Grant Nos.U1930401,11974410,11820101003,11921004 and 11534016)the National Key R&D Program of China(Grant Nos.2018YFA0305703,2018YFA0305700 and 2017YFA0302900).
文摘Recently,a series of novel compounds Ba3MX5(M=Fe,Ti,V;X=Se,Te)with hexagonal crystal structures composed of quasi-1-dimensional(1D)magnetic chains has been synthesized by our research team using high-pressure and high-temperature methods.The initial hexagonal phases persist to the maximum achievable pressure,while spin configurations and magnetic interactions may change dramatically as a result of considerable reductions in interchain separations upon pressurization.These compounds therefore offer unique possibilities for studying the evolution of intrinsic electronic structures in quasi-1D magnetic systems.Here we present a systematic investigation of Ba9Fe3Te15,in which the interchain separations between trimerized 1D chains(~10.2Å)can be effectively modulated by external high pressure.The crystal structure especially along the 1D chains exhibits an abnormal expansion at^GPa,which accompanies trimerization entangled anomalous mixed-high-low spin transition.An insulator-metal transition has been observed under high pressure as a result of charge-transfer gap closing.Pressure-induced superconductivity emerges at 26 GPa,where the charge-transfer gap fully closes,3D electronic configuration forms and local spin fully collapses.
基金Support from NSF(CMMI-1943710,DMR-2246991,and XSEDE MSS170015)Army Research Office(W911NF2420145)+3 种基金Iowa State University(Vance Coffman Faculty Chair Professorship and Murray Harpole Chair in Engineering)for VIL and AD is greatly appreciatedAD also acknowledges support from INTERN supplement to NSF grant CMMI-1943710 and from HPCAT for an internship at HPCATKKP was supported by NSF(CMMI-1943710)and ISUNV work performedunder the auspicesof the U.S.Department of Energy by Lawrence Livermore National Laboratory underContractDE-AC52-07NA27344。
文摘Plastic strain-induced phase transformations(PTs)and chemical reactions under high pressure are broadly spread in modern technologies,friction and wear,geophysics,and astrogeology.However,because of very heterogeneous fields of plastic strain Ep and stressσtensors and volume fraction c of phases in a sample compressed in a diamond anvil cell(DAC)and impossibility ofmeasurements ofσand Ep,there are no strict kinetic equations for them.Here,we develop a kineticmodel,finite element method(FEM)approach,and combined FEM-experimental approaches to determine all fields in strongly plastically predeformed Zr compressed in DAC,and specific kinetic equation forα-ωPT consistent with experimental data for the entire sample.Since all fields in the sample are very heterogeneous,data are obtained for numerous complex 7D paths in the space of 3 components of the plastic strain tensor and 4 components of the stress tensor.Kinetic equation depends on accumulated plastic strain(instead of time)and pressure and is independent of plastic strain and deviatoric stress tensors,i.e.,it can be applied for various above processes.Our results initiate kinetic studies of strain-induced PTs and provide efforts toward more comprehensive understanding of material behavior in extreme conditions.
基金supported by the National Key R&D Program of China(Grants No.2018YFA0703400)the National Natural Science Foundation of China(Grants Nos.51672238,91963203,51722209,and 51525205)+2 种基金M.Hu acknowledges fellowship support by the Alexander von Humboldt Foundation.Z.Zhao acknowledges 100 talents plan of Hebei Province(Grants No.E2016100013)NSF for Distinguished Young Scholars of Hebei Province of China(Grants No.E2018203349)K.Luo acknowledges the China Postdoctoral Science Foundation(Grants No.2017M620097).
文摘Glassy carbon(GC)is a type of non-graphitizing disordered carbon material at ambient pressure and high temperatures,which has been widely used due to its excellent mechanical properties.Here we report the changes in the microstructure and mechanical properties of GC treated at high pressures(up to 5 GPa)and high temperatures.The formation of intermediate sp2-sp3 phases is identified at moderate treatment temperatures before the complete graphitization of GC,by analyzing synchrotron X-ray diffraction,Raman spectra,and transmission electron microscopy images.The intermediate metastable carbon materials exhibit superior mechanical properties with hardness reaching up to 10 GPa and compressive strength reaching as high as 2.5 GPa,nearly doubling those of raw GC,and improving elasticity and thermal stability.The synthesis pressure used in this study can be achieved in the industry on a commercial scale,enabling the scalable synthesis of this type of strong,hard,and elastic carbon materials.
