摘要
A time-resolved x-ray diffraction technique is employed to monitor the structural transformation of laser-shocked bismuth.Results reveal a retarded transformation from the shock-induced Bi-Ⅴphase to a metastable Bi-Ⅳphase during the shock release,instead of the thermodynamically stable Bi-Ⅲphase.The emergence of the metastable Bi-Ⅳphase is understood by the competitive interplay between two transformation pathways towards the Bi-Ⅳand Bi-Ⅲ,respectively.The former is more rapid than the latter because the Bi-Ⅴto B-Ⅳtransformation is driven by interaction between the closest atoms while the Bi-Ⅴto B-Ⅲtransformation requires interaction between the second-closest atoms.The nucleation time for the Bi-Ⅴto Bi-Ⅳtransformation is determined to be 5.1±0.9 ns according to a classical nucleation model.This observation demonstrates the importance of the formation of the transient metastable phases,which can change the phase transformation pathway in a dynamic process.
作者
李江涛
王倩男
徐亮
柳雷
张航
Sota Takagi
Kouhei Ichiyanagi
Ryo Fukaya
Shunsuke Nozawa
胡建波
Jiangtao Li;Qiannan Wang;Liang Xu;Lei Liu;Hang Zhang;Sota Takagi;Kouhei Ichiyanagi;Ryo Fukaya;Shunsuke Nozawa;Jianbo Hu(Laboratory for Shock Wave and Detonation Physics Research,Institute of Fluid Physics,China Academy of Engineering Physics,Mianyang 621900,China;State Key Laboratory for Environment-Friendly Energy Materials,Southwest University of Science and Technology,Mianyang 621010,China;Japan Society for the Promotion of Science,Tokyo,102-0083,Japan;Institute of Materials Structure Science,High Energy Accelerator Research Organization,Ibaraki,305-8572,Japan)
基金
supported by the National Natural Science Foundation of China (Grant No.12072331)
the Science Challenge Project (Grant No.TZ2018001)
the Japan Society for the Promotion of Science (Grant Nos.17H04820 and 21H01677)
the Foundation of the United Laboratory of High-Pressure Physics and Earthquake Science
performed under the approval of the Photon Factory Program Advisory Committee (Proposal Nos.2016S2-006 and 2020G680)。
