Abstract
Numerical simulation techniques were used to study the vibrational properties of random networks. The networks, containing up to 1500 ions, were generated by the introduction of a large number of defects in regular crystals. Periodic boundary conditions were imposed. Long-range Coulomb effects were included for the first time. Our simulations reveal the existence of long-wavelength optic-type excitations which exhibit LO-TO splitting similar to crystalline solids. The LO-mode has a negative dispersion, whereas almost no dispersion is observed for the TO-mode. In the density of states, the TO-mode shows up as a peak, whereas the LO-mode defines the high frequency band edge.
Original language | English (US) |
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Pages (from-to) | 393-398 |
Number of pages | 6 |
Journal | Journal of Non-Crystalline Solids |
Volume | 75 |
Issue number | 1-3 |
DOIs | |
State | Published - Oct 1985 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry