Spontaneous decay of a soft optical phonon in the relaxor ferroelectric PbMg1/3Nb2/3O3

C. Stock*, P. M. Gehring, R. A. Ewings, Z. G. Xu, J. Li, D. Viehland, H. Luo

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

We report the spontaneous decay of a soft, optical phonon in a solid. Using neutron spectroscopy, we find that specific phonon lifetimes in the relaxor PbMg(1/3)Nb(2/)3O(3) are anomalously short within well-defined ranges of energy and momentum. This behavior is independent of ferroelectric order and occurs when the optical phonon with a specific energy and momentum can kinematically decay into two acoustic phonons with lower phase velocity. We interpret the well-known relaxor "waterfall" effect as a form of quasiparticle decay analogous to that previously reported in quantum spin liquids and quantum fluids.

Original languageEnglish
Article number024404
Number of pages6
JournalPhysical Review Materials
Volume2
Issue number2
DOIs
Publication statusPublished - 13 Feb 2018

Keywords

  • INELASTIC NEUTRON-SCATTERING
  • X-RAY-SCATTERING
  • SINGLE-CRYSTALS
  • PHASE-TRANSITIONS
  • LEAD MAGNONIOBATE
  • LATTICE-DYNAMICS
  • BEHAVIOR
  • MODE
  • PB(MG1/3NB2/3)O-3
  • TEMPERATURES

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