title: Lattice dynamics of dense lithium.
abstract: We report low-frequency high-resolution Raman spectroscopy and ab-initio calculations on dense lithium from 40 to 200 GPa at low temperatures. Our experimental results reveal rich first-order Raman activity in the metallic and semiconducting phases of lithium. The computed Raman frequencies are in excellent agreement with the measurements. Free energy calculations provide a quantitative description and physical explanation of the experimental phase diagram only when vibrational effect are correctly treated. The study underlines the importance of zero-point energy in determining the phase stability of compressed lithium.
authors.affiliation: LENS, European Laboratory for Non-Linear Spectroscopy, University of Florence, I-50121 Florence, Italy.
authors.forename: F A
authors.initials: FA
authors.lastname: Gorelli
authors.forename: S F
authors.initials: SF
authors.lastname: Elatresh
authors.forename: C L
authors.initials: CL
authors.lastname: Guillaume
authors.forename: M
authors.initials: M
authors.lastname: Marqués
authors.forename: G J
authors.initials: GJ
authors.lastname: Ackland
authors.forename: M
authors.initials: M
authors.lastname: Santoro
authors.forename: S A
authors.initials: SA
authors.lastname: Bonev
authors.forename: E
authors.initials: E
authors.lastname: Gregoryanz