title: In situ study on atomic mechanism of melting and freezing of single bismuth nanoparticles.
abstract: Experimental study of the atomic mechanism in melting and freezing processes remains a formidable challenge. We report herein on a unique material system that allows for in situ growth of bismuth nanoparticles from the precursor compound SrBi2Ta2O9under an electron beam within a high-resolution transmission electron microscope (HRTEM). Simultaneously, the melting and freezing processes within the nanoparticles are triggered and imaged in real time by the HRTEM. The images show atomic-scale evidence for point defect induced melting, and a freezing mechanism mediated by crystallization of an intermediate ordered liquid. During the melting and freezing, the formation of nucleation precursors, nucleation and growth, and the relaxation of the system, are directly observed. Based on these observations, an interaction-relaxation model is developed towards understanding the microscopic mechanism of the phase transitions, highlighting the importance of cooperative multiscale processes.
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics &Chemistry, Chinese Academy of Sciences, Urumqi 830011, China.|Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China.
authors.forename: Yingxuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Nano Institute of Utah and Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Zang
authors.affiliation: Nano Institute of Utah and Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Jacobs
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics &Chemistry, Chinese Academy of Sciences, Urumqi 830011, China.|Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics &Chemistry, Chinese Academy of Sciences, Urumqi 830011, China.|Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China.
authors.forename: Xiu
authors.initials: X
authors.lastname: Yue
authors.affiliation: Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics &Chemistry, Chinese Academy of Sciences, Urumqi 830011, China.|Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, China.
authors.forename: Chuanyi
authors.initials: C
authors.lastname: Wang