高压物理学报2019，Vol.33Issue(5)：46-57,12.DOI:10.11858/gywlxb.20180698
氦在方解石和文石中的扩散:基于第一性原理的研究
Diffusion of Helium in Calcite and Aragonite:A First-Principles Study
摘要
Abstract
Helium diffusion in carbonate minerals is important for studying the physical and chemical properties and dynamic processes of Earth's degassing.This paper discussed helium incorporation and diffusion mechanism in crystals of calcite and aragonite based on density functional theory calculations.The diffusion pathways,activation energies (Ea),and frequency factors (v) of helium under the surface and mantle condition were calculated.Calculations show an apperant anisotropy of helium diffusion in calcite,with more energetically favorable directions along a(b) axis.The moderate anisotropy of helium diffusion is showed in aragonite,in which the diffusion rate along c axis is slower than that along a axis.Under high pressure conditions,the activation energies of helium diffusion in aragonite increase with pressure.The closure temperature for calcite crystal varies from-54 ℃ to-25 ℃ in the direction [010],and for aragonite varies from-12 ℃ to 23 ℃ in [100].Aragonite may be more retentive for helium than calcite under surface condition,which agrees well with previous experimental studies.关键词
氦的扩散/方解石/文石/第一性原理/压力效应Key words
helium diffusion/calcite/aragonite/ab initio/pressure effect分类
数理科学引用本文复制引用
李书晨,刘红,杨耀春,丁建华,刘雷,李营,易丽,田华..氦在方解石和文石中的扩散:基于第一性原理的研究[J].高压物理学报,2019,33(5):46-57,12.基金项目
National Natural Science Foundation of China (41174071,41573121) （41174071,41573121）
Seismic Fund of Institute of Earthquake Forecasting,China Earthquake Administration (CEA) (2016IES0101) （CEA）
