The boson peak in melt-formed and damage-formed glasses: A defect signature?

M. Harish Bhat, Inmaculada Peral, John R D Copley, Charles Angell

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

We describe the preparation and characterization of a glassy form of the moderately good glassformer PbGeO3, by mechanical damage, and compare its properties with those of the normal melt-quenched glass and the crystal. The damage-formed glass exhibits a DSC thermogram strikingly similar to that of a hyperquenched glass, implying that it forms high on the energy landscape. The final glass transition endotherm occurs within 4 K (0.006Tg) of that of the melt-quenched glass, but crystallization occurs at a lower temperature, as if pre-nucleated. In particular, we have studied the low frequency vibrational dynamics of the alternatively prepared amorphous states in the boson peak region, and find the damage-formed glass boson peak to be almost identical in shape to, but more intense than, that of the normal melt-formed glass, as previously found for hyperquenched glasses. In view of the quite different preparation procedures, this similarity would seem to eliminate equilibrium liquid clusters as a source of the boson peak vibrations, but leaves plausible a connection to force constant fluctuations or to specific vitreous state defects.

Original languageEnglish (US)
Pages (from-to)4517-4524
Number of pages8
JournalJournal of Non-Crystalline Solids
Volume352
Issue number42-49 SPEC. ISS.
DOIs
StatePublished - Nov 15 2006

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Keywords

  • Defects
  • Electron diffraction/scattering
  • Enthalpy relaxation
  • Germanates
  • Glass transition
  • Heavy metal oxides
  • Medium-range order
  • Neutron diffraction/scattering
  • Phonons
  • Scanning electron microscopy
  • Terahertz properties and measurements
  • Thermodynamics
  • X-ray diffraction

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Materials Chemistry

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