title: First-order liquid-liquid phase transition in cerium.
abstract: We report the first experimental observation of a liquid-liquid phase transition in the monatomic liquid metal cerium, by means of in situ high-pressure high-temperature x-ray diffraction experiments. At 13 GPa, upon increasing temperature from 1550 to 1900 K high-density liquid transforms to a low-density liquid, with a density difference of 14%. Theoretic models based on ab initio calculations are built to investigate the observed phase behavior of the liquids at various pressures. The results suggest that the transition primarily originates from the delocalization of f electrons and is deemed to be of the first order that terminates at a critical point.
authors.affiliation: School of Physics, Astronomy and Computational Sciences, George Mason University, Fairfax, Virginia 22030, USA.
authors.forename: A
authors.initials: A
authors.lastname: Cadien
authors.affiliation: School of Physics, Astronomy and Computational Sciences, George Mason University, Fairfax, Virginia 22030, USA.
authors.forename: Q Y
authors.initials: QY
authors.lastname: Hu
authors.affiliation: High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Meng
authors.affiliation: Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Cheng
authors.affiliation: WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
authors.forename: M W
authors.initials: MW
authors.lastname: Chen
authors.affiliation: Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Shu
authors.affiliation: High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA and Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA.
authors.forename: H K
authors.initials: HK
authors.lastname: Mao
authors.affiliation: School of Physics, Astronomy and Computational Sciences, George Mason University, Fairfax, Virginia 22030, USA and Center for Computational Materials Science, George Mason University, Fairfax, Virginia 22030, USA.
authors.forename: H W
authors.initials: HW
authors.lastname: Sheng