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 language | English (US) |
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Pages (from-to) | 4517-4524 |
Number of pages | 8 |
Journal | Journal of Non-Crystalline Solids |
Volume | 352 |
Issue number | 42-49 SPEC. ISS. |
DOIs | |
State | Published - Nov 15 2006 |
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