In situ study of calcite-Ⅲ dimorphism using dynamic diamond anvil cell  

作　　者：Xia Zhao Sheng-Hua Mei Zhi Zheng Yue Gao Jiang-Zhi Chen Yue-Gao Liu Jian-Guo Sun Yan Li Jian-Hui Sun 赵霞;梅升华;郑直;高悦;陈姜智;刘月高;孙建国;李艳;孙建辉(CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions,Institute of Deep-sea Science and Engineering,Chinese Academy of Sciences(CAS),Sanya 572000,China;University of Chinese Academy of Sciences,Beijing 100049,China;Department of Mechanical Engineering,National University of Singapore(NUS),Singapore 117575,Singapore)

机构地区：[1]CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions,Institute of Deep-sea Science and Engineering,Chinese Academy of Sciences(CAS),Sanya 572000,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Department of Mechanical Engineering,National University of Singapore(NUS),Singapore 117575,Singapore

出　　处：《Chinese Physics B》2022年第9期421-427,共7页中国物理B（英文版）

基　　金：Project supported by the Fund from the Chinese Academy of Sciences (Grant No. QYZDY-SSW-DQC029);the National Natural Science Foundation of China (Grant No. 41674097)

摘　　要：The phase transitions among the high-pressure polymorphic forms of CaCO_(3)(cc-Ⅰ,cc-Ⅱ,cc-Ⅲ,and cc-Ⅲb)are investigated by dynamic diamond anvil cell(dDAC)and in situ Raman spectroscopy.Experiments are carried out at room temperature and high pressures up to 12.8 GPa with the pressurizing rate varying from 0.006 GPa/s to 0.056 GPa/s.In situ observation shows that with the increase of pressure,calcite transforms from cc-Ⅰto cc-Ⅱat~1.5 GPa and from cc-Ⅱto cc-Ⅲat~2.5 GPa,and transitions are independent of the pressurizing rate.Further,as the pressure continues to increase,the cc-Ⅲb begins to appear and coexists with cc-Ⅲwithin a pressure range that is inversely proportional to the pressurizing rate.At the pressurizing rates of 0.006,0.012,0.021,and 0.056 GPa/s,the coexistence pressure ranges of cc-Ⅲand cc-Ⅲb are 2.8 GPa-9.8 GPa,3.1 GPa-6.9 GPa,2.7 GPa-6.0 GPa,and 2.8 GPa-4.5 GPa,respectively.The dependence of the coexistence on the pressurizing rate may result from the influence of pressurizing rate on the activation process of transition by reducing the energy barrier.The higher the pressurizing rate,the lower the energy barrier is,and the easier it is to pull the system out of the coexistence state.The results of this in situ study provide new insights into the understanding of the phase transition of calcite.

关 键 词：calcite-Ⅲ DIMORPHISM dynamic diamond anvil cell in situ Raman spectroscopy pressurizing rate 

分 类 号：O657.37[理学—分析化学] TB34[理学—化学]