Pressure Effects on the Transport and Structural Properties of Metallic Glass-Forming Liquid  

作　　者：Qi-Long Cao Duo-Hui Huang Jun-Sheng Yang Fan-Hou Wang 曹启龙;黄多辉;杨俊升;王藩侯(Key Laboratory of Computational Physics,Yibin University,Yibin 644007,China)

机构地区：[1]Key Laboratory of Computational Physics,Yibin University,Yibin 644007,China

出　　处：《Chinese Physics Letters》2020年第7期56-60,共5页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(Grant No.11704329.)。

摘　　要：Transport and structural properties of metallic glass-forming liquid Cu50Zr50 are investigated by molecular dynamics simulation,under high pressures from 1 bar to 70 GPa.The following results have been obtained:(i)reversals of component diffusion coefficients(DCu and DZr)are observed at the reversion pressure.At low pressures below the reversion pressure,DCu and DZr decreases from about 1.4 to 1.0.At high pressures above the reversion pressure,DCu and DZr decreases more rapidly from 1.0 to about 0.7.(ii)Component diffusion coefficients decay exponentially with pressure up to reversion pressure,then the strength of the exponential dependence changes,while the pressure-dependent behavior of viscosity can be well described by a single exponential relation over the full range of pressure.(iii)The Stokes–Einstein relation(SER)works well at low pressures and starts to be violated at the breakdown pressure.For glass-forming liquid Cu50 Zr50 along the 2000 K isotherm,the breakdown pressure equals the reversion pressure of component diffusion coefficients and is about 35 GPa.(iv)The pressure dependences of the ratio between component diffusion coefficients can be used to predict the breakdown pressure of SER along isotherm.The validity of SER and the reversals of component diffusion coefficients are found to be related to the pressure dependence of the relative total fractions of predominant Voronoi polyhedrons around individual components.

关 键 词：pressure. DIFFUSION ISOTHERM 

分 类 号：TG139.8[一般工业技术—材料科学与工程]