title: Direct observation of a pressure-induced precursor lattice in silicon.
abstract: Detailed knowledge of atomic-scale structural change is essential for understanding the process and mechanism of phase transitions in solids. We present the direct experimental evidence of a precursor lattice in silicon at high pressures. The precursor lattice may appear to coexist dynamically with the host lattice over a large pressure range through rapid lattice fluctuations. The first-principles calculations are used to elucidate a dynamic lattice-fluctuation mechanism that accounts for the experimental observations. This precursor lattice-fluctuation mechanism for the phase transition goes beyond previously considered reconstructive or displacive processes and provides a novel picture of the underlying dynamics.
authors.affiliation: High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA. gshen@ciw.edu
authors.forename: Guoyin
authors.initials: G
authors.lastname: Shen
authors.forename: Daijo
authors.initials: D
authors.lastname: Ikuta
authors.forename: Stanislav
authors.initials: S
authors.lastname: Sinogeikin
authors.forename: Quan
authors.initials: Q
authors.lastname: Li
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Changfeng
authors.initials: C
authors.lastname: Chen