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Evolution of electrical conductivity and semiconductor to metal transition of iron oxides at extreme conditions

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Chinese Physics B 2022年第8期31卷 95-100页

作者： yukai zhuang Qingyang Hu Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065China Center for High Pressure Science and Technology Advanced Research(HPSTAR) Beijing 100094China

Iron oxides are widely found as ores in Earth's crust and are also important constituents of its *** polymorphism,composition changes,and electronic structures play essential roles in controlling the structure and geodynamic properties of the solid *** all-natural occurring iron oxides are semiconductors or insulators at ambient pressure,they start to metalize under *** in this work,we review the electronic conductivity and metallization of iron oxides under high-pressure conditions found in Earth's lower *** summarize that the metallization of iron oxides is generally controlled by the pressure-induced bandgap closure near the Fermi *** metallization,they possess much higher electrical and thermal conductivity,which will facilitate the thermal convection,support a more stable and thicker D′′layer,and formulate Earth's magnetic field,all of which will constrain the large-scale dynamos of the mantle and core.

关键词： high pressure metallization iron oxides electrical conductivity

The effect of nitrogen on the compressibility and conductivity of iron at high pressure

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Geoscience Frontiers 2021年第2期12卷 983-989页

作者： yukai zhuang Xiaowan Su Nilesh P.Salke Zhongxun Cui Qingyang Hu Dongzhou Zhang Jin Liu Center for High Pressure Science and Technology Advanced Research(HPSTAR) Beijing 100094China School of Earth and Space Sciences Peking UniversityBeijing 100871China Hawai’i Institute of Geophysics and Planetology School of Ocean and Earth Science and TechnologyUniversity of Hawai’i at ManoaHonoluluHI96822USA

Although nitrogen in the Earth’s interior has attracted significant attention recently,it remains the most enigmatic of the light elements in the Earth’s *** this work,synchrotron X-ray diffraction(XRD)and electrical conductivity experiments were conducted on iron nitrides(Fe_(2)N and Fe_(4)N)in diamond anvil cells(DACs)up to about 70 GPa at ambient *** results show that iron nitrides are stable up to at least 70 *** the equation of state(EOS)parameters,iron nitrides are more compressible than iron ***,using the van der Pauw method and Wiedemann-Franz law,the electrical and thermal conductivity of samples were determined to be much lower than that of iron *** conductivities of Fe_(2)N and Fe_(4)N were similar at 20–70 GPa,suggesting no evident effects by varying the N stoichiometries in iron *** nitrides are less dense and conductive but more compressible than carbides at 0–70 *** study indicates that less nitrogen than carbon can explain geophysical phenomena in the deep Earth,such as the density deficit.

关键词： High pressure Iron nitrides Synchrotron X-ray diffraction Electrical conductivity

High Temperature Melting Curve of Basaltic Glass by Laser Flash Heating

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Chinese Physics Letters 2022年第2期39卷 15-20页

作者： yukai zhuang Junwei Li Wenhua Lu Xueping Yang Zhixue Du Qingyang Hu Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065China Center for High Pressure Science and Technology Advanced Research(HPSTAR) Beijing 100094China State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Center for Excellence in Deep Earth Science Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China

Basalt is an igneous rock originating from the cooling and solidification of magma and covers approximately 70% of Earth’s *** glass melting in the deep Earth is a fundamental subject of research for understanding geophysics,geochemistry,and geodynamic *** this study,we design a laser flash heating system using two-dimensional,four-color multi-wavelength imaging radiometry to measure the basaltic glass melting temperature under high pressure conditions in diamond anvil *** experiment not only determines the temperature at the center of heating but also constructs a temperature distribution map for the surface heating area,and enables us to assess the temperature *** precise temperature measurements,we observe that the basaltic glass melting temperature is higher than those in previous reports,which is near the normal upper-mantle isotherm,approaching the hot *** suggests that basalt should not melt in most of the normal upper mantle and the basaltic melts could exist in some hot regions.

关键词： basalt mantle Earth

The effect of iron on the sound velocities ofδ-AlOOH up to 135 GPa

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Geoscience Frontiers 2021年第2期12卷 937-946页

作者： Xiaowan Su Chaoshuai Zhao Chaojia Lv yukai zhuang Nilesh Salke Liangxu Xu Hu Tang Huiyang Gou Xiaohui Yu Qiang Sun Jin Liu School of Earth and Space Sciences Peking UniversityBeijing100871China Center for High Pressure Science and Technology Advanced Research Beijing100094China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing100190China

δ-(Al,Fe)OOH is considered to be one of the most important hydrous phases on Earth,remaining stable under the extreme conditions throughout the *** behavior ofδ-(Al,Fe)OOH at high pressure is essential to understanding the deep water cycle.δ-(Al_(0.956)Fe_(0.044))OOH crystals synthesized at 21 GPa and 1473 K were investigated by high-pressure Brillouin light scattering spectroscopy and synchrotron X-ray diffraction up to 135.4 GPa in diamond anvil *** incorporation of 5 mol%FeOOH increases the unit-cell volume ofδ-AlOOH by~1%and decreases the shear-wave velocity(VS)by~5%at 20–135 *** particular,the compressional(V_(P))and shear(VS)wave velocities ofδ-(Al_(0.956)Fe_(0.044))OOH are 7%–16%and 10%–24%greater than all the major minerals in the mantle transition zone including wadsleyite,ringwoodite,and *** distinctly high sound velocities ofδ-(Al_(0.956)Fe_(0.044))OOH at 20–25 GPa may contribute to the seismic anomalies observed at~560–680 km depths in the cold and stagnant slab beneath Izu-Bonin and/or ***,the VS ofδ-(Al_(0.956)Fe_(0.044))OOH is about 10%and 4%–12%lower than iron-bearing bridgmanite Mg_(0.96)Fe_(0.05)Si_(0.99O3)and ferropericlase(Mg_(0.92)Fe_(0.08))O,respectively,under the lowermost mantle conditions,which might partially contribute to the large low-shear-velocity provinces and ultralow velocity zones at the bottom of the lower mantle.

关键词： Deep water cycle Fe-bearing delta phase Seismic anomalies High pressure

Abnormal electrical conductivity of siderite across the spin transition

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Abnormal electrical conductivity of siderite across the spin...

Mid-mantle water transportation implied by the electrical and seismic properties ofε-FeOOH

2019年中国地球科学联合学术年会

作者： Chaoshuai Zhao Jie Zhu Xuehui Wei yukai zhuang Jung-Fu Lin Liuxiang Yang Jin Liu Center for High Pressure Science and Technology Advanced Research College of Science Guizhou Institute of Technology Jackson School of Geosciences The University of Texas at Austin

Siderite(FeCO3) is one of the most important deep-carbon carriers in the deep mantle. Knowledge of its stability, incompressibility, and electrical conductivity(EC) at high pressure is of utmost importance to better interpret the deep carbon cycling as well as to search for carbonate-enriched domains in the Earth's interior. However, the EC of siderite is scarcely investigated under P-T conditions relevant to the mid-mantle. Combined with laser Raman spectroscopy and X-ray diffraction(XRD) measurements, the EC of siderite has been determined up to 83.3 GPa at room temperature. The low-temperature EC measurements were down to 126 K at 21 and 62 GPa, respectively. We found that the EC of siderite dramatically increases across the electronic spin-pairing transition of iron between 38 and 50 GPa(corresponding to depths of approximate 1000-1200 km), associated with a large reduction in volume by 8-9% leading to higher electron density in the FeCO3 lattice. Moreover, the derived activation enthalpy, activation energy and activation volume of siderite at 21 GPa are 0.217 eV, 0.227 eV and-0.048 cm3/mole for the high-spin state, and that at 62 GPa are 0.122 eV, 0.157 eV and-0.054 cm3/mole for the low-spin state. The EC mechanism of siderite is thus the small polaron conduction at low and room temperature. These results suggest that the abnormal EC of siderite within a narrow pressure range may cause local EC anomalies in remnants of deep subducting slabs in the mid-mantle where siderite might accumulate. In particular, compared with the EC and thermal conductivity(TC) of major phases in the lower mantle, the EC and TC of siderite is relatively large across the spin transition at 40-50 GPa [Chao and Hsieh, 2019;Lin et al., 2007;Liu et al., 2018;Yoshino et al., 2011]. It likely contributes local high conductivity and thermal anomalies in the mid-lower mantle, especially at depths of 1000-1200 km.

关键词： Deep carbon cycle electrical conductivity siderite high pressure

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Science Bulletin 2022年第7期67卷 748-754页

作者： yukai zhuang Bo Gan Zhongxun Cui Ruilian Tang Renbiao Tao Mingqiang Hou Gang Jiang Catalin Popescu Gaston Garbarino Youjun Zhang Qingyang Hu Center for High Pressure Science and Technology Advanced Research Beijing 100094China Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065China School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Geodesy and Earth’s Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China Consorcio para la Construcción Equipamiento y Explotación del Laboratorio de Luz de SincrotrónCerdanyola del VallèsBarcelona 08290Spain European Synchrotron Radiation Facility Grenoble 38000France International Center for Planetary Science College of Earth SciencesChengdu University of TechnologyChengdu 610059China Center for Excellence in Deep Earth Science Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China

Water in the mantle transition zone and the core-mantle boundary plays a key role in Earth’s stratification,volatile cycling,and core *** water transportation is actively running between the aforementioned layers,the lower mantle should contain water channels with distinctive seismic and/or electromagnetic ***,we investigated the electrical conductivity and sound velocity ofε-FeOOH up to 71 GPa and 1800 K and compared them with global tomography *** abrupt threeorder jump of electrical conductivity was observed above 50 GPa,reaching 1.24(12)×10^(3)S/m at 61 ***,the longitudinal sound velocity dropped by 16.8%in response to the high-to-low spin transition of Fe^(3+).The high-conductivity and low-sound velocity ofε-FeOOH match the features of heterogenous scatterers in the mid-lower *** unique properties of hydrousε-FeOOH,or possibly other Fe-enriched phases can be detected as evidence of active water transportation in the mid-lower mantle.

关键词： Mid-lower mantle Electrical conductivity Seismic velocity Heterogeneity

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柴北缘构造带泥盆纪构造属性研究

中国石油大学学报（自然科学版） 2015年第2期39卷 23-30页

作者：孙娇鹏陈世悦彭渊刘文平庄毓凯中国石油大学地球科学与技术学院山东青岛266580 中国地质科学院地质力学研究所北京100081 中国石油西南油气田公司勘探开发研究院四川成都610051

根据露头及钻井资料,依据沉积学理论,对柴达木盆地东北部泥盆系地层厚度、碎屑颗粒组成、锆石年龄、超覆关系和沉积体系展布等进行研究。结果表明：柴北缘地区（包括柴北缘构造带与欧龙布鲁克微板块）泥盆纪发育自南向北展布的沉积体系... 详细信息

根据露头及钻井资料,依据沉积学理论,对柴达木盆地东北部泥盆系地层厚度、碎屑颗粒组成、锆石年龄、超覆关系和沉积体系展布等进行研究。结果表明：柴北缘地区（包括柴北缘构造带与欧龙布鲁克微板块）泥盆纪发育自南向北展布的沉积体系,碎屑物质来源于由多个前泥盆纪构造岩片组成的造山带;该阶段柴北缘构造带构造属性既不是前陆盆地也不是裂陷槽,而是由多个前泥盆纪构造岩片组成的造山带;该造山带隆升开始于距今约465 Ma,遭受剥蚀开始于距今约430 Ma,其隆升可能持续到晚石炭世甚至二叠纪早期,初步推断该造山带至少存在了190 Ma,包括距今465～430 Ma的山体隆升与距今430～275 Ma的山体剥蚀阶段。

关键词：柴北缘构造带泥盆纪碎屑组成沉积体系展布构造属性

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二次氯化—二次还原法精炼高纯金工艺研究

黄金 2014年第2期35卷 57-60页

作者：庄宇凯纪鹏山东招金金银精炼有限公司

采用二次氯化—二次还原法进行了金精炼提纯工艺研究与实践。该工艺主要由粗金粉化、一次氯化浸金、一次还原金、二次氯化浸金、二次还原金、熔炼等环节组成。经实践表明,采用该工艺获得的金纯度可达到99.999%以上,且该工艺流程简单、... 详细信息

采用二次氯化—二次还原法进行了金精炼提纯工艺研究与实践。该工艺主要由粗金粉化、一次氯化浸金、一次还原金、二次氯化浸金、二次还原金、熔炼等环节组成。经实践表明,采用该工艺获得的金纯度可达到99.999%以上,且该工艺流程简单、设备合理、生产周期短。

关键词：二次氯化-二次还原精炼提纯高纯金

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柴北缘上古生界混合沉积特征及控制因素

地质通报 2016年第2期35卷 282-292页

作者：陈世悦毕明威孙娇鹏张跃庄毓凯刘金汪峰马帅中国石油大学(华东)地球科学与技术学院山东青岛266580 中山大学地球科学与地质工程学院广东广州510275 西北大学大陆动力学国家重点实验室/地质学系陕西西安710069 中石化江苏油田试采一厂江苏扬州225400

柴北缘晚古生代发育多种成因机理各异的混积岩与混积层系。混积岩分为蚀源型砂砾岩,碳酸盐岩-粗陆源碎屑混积岩,泥灰岩(灰泥岩)与含化石泥岩三大类。混积层系在不同环境中均有出现,混积相可划分为混积砂砾质碎屑海岸相、混积低能海岸相... 详细信息

柴北缘晚古生代发育多种成因机理各异的混积岩与混积层系。混积岩分为蚀源型砂砾岩,碳酸盐岩-粗陆源碎屑混积岩,泥灰岩(灰泥岩)与含化石泥岩三大类。混积层系在不同环境中均有出现,混积相可划分为混积砂砾质碎屑海岸相、混积低能海岸相、混积台地、混积陆棚4类。在此基础上对各类混积岩、混积层系进行了沉积环境、形成机制解释,归纳出3种不同时期的混积相组合并建立沉积模式。构造运动、海平面升降、气候及古坡角的共同作用导致该区混合沉积普遍发育。其中,加里东构造带的存在及近物源沉积是粗碎屑与生屑颗粒混合的先决条件,海平面频繁变化与极缓的古坡角是该区混积岩、混积层系高频发育的直接原因。

关键词：柴北缘上古生界混合沉积沉积特征控制因素