@article{Smith2018,
title = {Temperature dependence of phonons in FeGe2},
author = {Hillary L. Smith and Yang Shen and Dennis S. Kim and Fred C. Yang and C.P. Adams and Chen W. Li and D.L. Abernathy and M.B. Stone and B. Fultz},
url = {https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.2.103602},
doi = {10.1103/PhysRevMaterials.2.103602},
year = {2018},
date = {2018-10-09},
journal = {Physical Review Materials},
volume = {2},
pages = {103602},
abstract = {Inelastic neutron scattering was used to measure phonon dispersions in a single crystal of FeGe2 with the C16 structure at 300, 500, and 635 K. Phonon densities of states (DOS) were also measured on polycrystalline FeGe2 from 325 to 1050 K, and the Fe partial DOS was obtained from polycrystalline
57 FeGe2 at 300 K using nuclear resonant inelastic x-ray scattering. The dominant feature in the temperature dependence of the phonon spectrum is thermal broadening of high-energy modes. The energy shifts of the low- and high-energy parts of the spectrum were almost the same. DFT calculations performed with the quasiharmonic approximation gave results in moderate agreement with the experimental thermal energy shifts, although the isobaric Grüneisen parameter calculated from the quasiharmonic model was smaller than that from measurements. The thermal broadening of the phonon spectrum and dispersions, especially at high energies, indicates a cubic anharmonicity to second order that should also induce phonon shifts. We show that different anharmonic contributions cancel out, giving average phonon shifts in moderate agreement to calculations with the quasiharmonic approximation. The different parts of the large phonon contribution to the entropy are separated for FeGe2, showing modest but interpretable anharmonic contributions.},
keywords = {anharmonicity, high temperature, lattice expansion, magnetism, phonon, vibrational entropy},
pubstate = {published},
tppubtype = {article}
}

@article{Smith:2017goa,
title = {Separating the configurational and vibrational entropy contributions in metallic glasses},
author = {H L Smith and Chen W Li and A Hoff and G R Garrett and D S Kim and F C Yang and M S Lucas and T Swan-Wood and J Y Y Lin and M B Stone and D L Abernathy and M D Demetriou and B Fultz},
url = {http://www.nature.com/doifinder/10.1038/nphys4142},
doi = {10.1038/nphys4142},
year = {2017},
date = {2017-01-01},
journal = {Nature Physics},
volume = {13},
number = {9},
pages = {900-905},
keywords = {metallic glass, neutron, phase transition, phonon, thermodynamics, vibrational entropy},
pubstate = {published},
tppubtype = {article}
}

@article{Shen2016,
title = {honon anharmonicity and components of the entropy in palladium and platinum},
author = {Shen, Yang and Li, Chen W. and Tang, Xiaoli and Smith, Hillary L. and Fultz, B.},
url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.93.214303},
doi = {10.1103/PhysRevB.93.214303},
year = {2016},
date = {2016-06-07},
journal = {Physical Review B},
volume = {93},
pages = {214303},
abstract = {Inelastic neutron scattering was used to measure the phonon density of states in fcc palladium and platinum metal at temperatures from 7 K to 1576 K. Both phonon-phonon interactions and electron-phonon interactions were calculated by methods based on density functional theory (DFT) and were consistent with the measured shifts and broadenings of phonons with temperature. Unlike the longitudinal modes, the characteristic transverse modes had a nonlinear dependence on temperature owing to the requirement for a population of thermal phonons for upscattering. Kohn anomalies were observed in the measurements at low temperature and were reproduced by calculations based on DFT. Contributions to the entropy from phonons and electrons were assessed and summed to obtain excellent agreement with prior calorimetric data. The entropy from thermal expansion is positive for both phonons and electrons but larger for phonons. The anharmonic phonon entropy is negative in Pt, but in Pd it changes from positive to negative with increasing temperature. Owing to the position of the Fermi level on the electronic DOS, the electronic entropy was sensitive to the adiabatic electron-phonon interaction in both Pd and Pt. The adiabatic EPI depended strongly on thermal atom displacements.},
keywords = {anharmonicity, neutron, phonon, vibrational entropy},
pubstate = {published},
tppubtype = {article}
}

@article{budai_metallization_2014,
title = {Metallization of vanadium dioxide driven by large phonon entropy},
author = {J D Budai and J Hong and M E Manley and E D Specht and Chen W Li and J Z Tischler and D L Abernathy and A H Said and B M Leu and L A Boatner and R J McQueeney and O Delaire},
url = {http://www.nature.com/doifinder/10.1038/nature13865},
doi = {10.1038/nature13865},
year = {2014},
date = {2014-11-01},
journal = {Nature},
volume = {515},
number = {7528},
pages = {535-539},
keywords = {anharmonicity, metal-insulator transition, neutron, phonon, synchrotron, thermodynamics, vibrational entropy},
pubstate = {published},
tppubtype = {article}
}

@article{munoz_positive_2011,
title = {Positive Vibrational Entropy of Chemical Ordering in FeV},
author = {J A Munoz and M S Lucas and O Delaire and M L Winterrose and L Mauger and Chen W Li and A O Sheets and M B Stone and D L Abernathy and Y Xiao and P Chow and B Fultz},
url = {https://link.aps.org/doi/10.1103/PhysRevLett.107.115501},
doi = {10.1103/PhysRevLett.107.115501},
year = {2011},
date = {2011-09-01},
journal = {Physical Review Letters},
volume = {107},
number = {11},
pages = {115501},
keywords = {Fe, neutron, synchrotron, vibrational entropy},
pubstate = {published},
tppubtype = {article}
}

@article{lucas_effects_2010,
title = {Effects of chemical composition and B2 order on phonons in bcc Fe–Co alloys},
author = {M S Lucas and J A Munoz and L Mauger and Chen W Li and A O Sheets and Z Turgut and J Horwath and D L Abernathy and M B Stone and O Delaire and Y Xiao and B Fultz},
url = {http://aip.scitation.org/doi/10.1063/1.3456500},
doi = {10.1063/1.3456500},
year = {2010},
date = {2010-01-01},
journal = {Journal of Applied Physics},
volume = {108},
number = {2},
pages = {023519},
keywords = {Fe, phonon, vibrational entropy},
pubstate = {published},
tppubtype = {article}
}