Hydrogen-Bond Symmetrization of δ-AlOOH  

作　　者：Duan Kang Ye-Xin Feng Ying Yuan Qi-Jun Ye Feng Zhu Hao-Yan Huo Xin-Zheng Li Xiang Wu 康端;冯页新;袁颖;叶麒俊;朱峰;霍浩岩;李新征;巫翔(Key Laboratory of Orogenic Belts and Crustal Evolution (Ministry of Education), School of Earth and Space Sciences, Peking University, Beijing 100871;School of Physics and Electronics, Hunan Universitz Changsha 410081;School of Physics and Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871;State Key Laboratory of Geological Processes and Mineral Resources, China University of Oeoseiences, Wuhan 430074)

机构地区：[1]Key Laboratory of Orogenic Belts and Crustal Evolution （Ministry of Education）, School of Earth and Space Sciences, Peking University, Beijing 100871 [2]School of Physics and Electronics, Hunan University,Changsha 410081 [3]School of Physics and Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871 [4]State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074

出　　处：《Chinese Physics Letters》2017年第10期95-99,共5页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos U1232204,41473056,11422431 and 11634001;the National Key Research and Development Program of China under Grant No 2016YFA0300901;the National Basic Research Program of China under Grant No 2013CB934600

摘　　要：The 6-AIOOH can transport water into the deep mantle along cold subducting slab geotherm. We investigate the hydrogen-bond symmetrization behavior of 6-AIOOH under the relevant pressure-temperature condition of the lower mantle using ab initio molecular dynamics （MD）. The static symmetrization pressure of 30.0 GPa can be reduced to 17.0 GPa at 30014 by finite-temperature （T） statistics, closer to the experimental observation of ~10.0 GPa. The symmetrization pressure obtained by MD simulation is related to T by P （GPa） = 13.9 （GPa） ＋ 0.01 （GPa/K） x T （K）. We conclude that 6-AIOOH in the lower mantle exists with symmetric hydrogen bond from its birthplace, or someplace slightly deeper, to the core-mantle boundary （CM13） along cold subducting slab geotherm, The bulk modulus decreases with T and increases anomalously upon symmetrization： Ko （GPa） = 181 （GPa） - 0,013 （GPa/K） x T （K） for 6-AIOOH with asymmetric hydrogen bond, and Ko （OPa） = 216 （GPa） - 0.013 （GPa/K） × T （K） for 6-AIOOH with symmetric hydrogen bond. Our results provide an important insight into the existent form and properties of 6-AIOOH in the lower mantle.The 6-AIOOH can transport water into the deep mantle along cold subducting slab geotherm. We investigate the hydrogen-bond symmetrization behavior of 6-AIOOH under the relevant pressure-temperature condition of the lower mantle using ab initio molecular dynamics （MD）. The static symmetrization pressure of 30.0 GPa can be reduced to 17.0 GPa at 30014 by finite-temperature （T） statistics, closer to the experimental observation of ~10.0 GPa. The symmetrization pressure obtained by MD simulation is related to T by P （GPa） = 13.9 （GPa） ＋ 0.01 （GPa/K） x T （K）. We conclude that 6-AIOOH in the lower mantle exists with symmetric hydrogen bond from its birthplace, or someplace slightly deeper, to the core-mantle boundary （CM13） along cold subducting slab geotherm, The bulk modulus decreases with T and increases anomalously upon symmetrization： Ko （GPa） = 181 （GPa） - 0,013 （GPa/K） x T （K） for 6-AIOOH with asymmetric hydrogen bond, and Ko （OPa） = 216 （GPa） - 0.013 （GPa/K） × T （K） for 6-AIOOH with symmetric hydrogen bond. Our results provide an important insight into the existent form and properties of 6-AIOOH in the lower mantle.

关 键 词：Hydrogen-Bond Symmetrization of AlOOH 

分 类 号：O641.1[理学—物理化学]