Comparing the Descriptors for Investigating the Influence of Lattice Dynamics on Ionic Transport Using the Superionic Conductor Na3PS4-xSex

Thorben Krauskopf, Sokseiha Muy, Sean P. Culver, Saneyuki Ohno, Olivier Delaire, Yang Shao-Horn, Wolfgang G. Zeier

Research output: Contribution to journalArticlepeer-review

60 Citations (Scopus)

Abstract

Recent work on superionic conductors has demonstrated the influence of lattice dynamics and the softness of the lattice on ionic transport. When examining either the changes in the acoustic phonon spectrum or the whole phonon density of states, both a decreasing activation barrier of migration and a decreasing entropy of migration have been observed, highlighting that the paradigm of "the softer the lattice, the better" does not always hold true. However, both approaches to monitor the changing lattice dynamics probe different frequency ranges of the phonon spectrum, and thus, it is unclear if they are complementary. In this work, we investigate the lattice dynamics of the superionic conductor Na3PS4-xSex by probing the optical phonon modes and the acoustic phonon modes, as well as the phonon density of states via inelastic neutron scattering. Notably, Raman spectroscopy shows the evolution of multiple local symmetry reduced polyhedral species, which likely affect the local diffusion pathways. Meanwhile, density functional theory and the ionic transport data are used to compare the different approaches for assessing the lattice dynamics. This work shows that, while acoustic and inelastic methods may be used to experimentally assess the overall changing lattice stiffness, calculations of the average vibrational energies between the mobile ions and the anion framework are important to assess and computationally screen for ionic conductors.

Original languageEnglish
Pages (from-to)14464-14473
Number of pages10
JournalJournal of the American Chemical Society
Volume140
Issue number43
DOIs
Publication statusPublished - Oct 31 2018
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Fingerprint

Dive into the research topics of 'Comparing the Descriptors for Investigating the Influence of Lattice Dynamics on Ionic Transport Using the Superionic Conductor Na<sub>3</sub>PS<sub>4-x</sub>Se<sub>x</sub>'. Together they form a unique fingerprint.

Cite this