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Phonon anomaly in high-pressure Zn
1Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6.
Physical Review Letters
|December 2, 2000
Summary
This study calculates the equation of state and phonon dispersions for hexagonal zinc using advanced computational methods. Results reveal electronic topological transitions impacting acoustic phonon frequencies under pressure.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Computational Materials Science
Background:
- Hexagonal zinc exhibits complex behavior under pressure.
- Understanding its equation of state and lattice dynamics is crucial for materials science applications.
Purpose of the Study:
- To calculate the equation of state and phonon dispersions of hexagonal zinc.
- To investigate the effects of pressure on zinc's structural and vibrational properties.
- To explore the relationship between electronic topological transitions and phonon behavior.
Main Methods:
- Plane-wave pseudopotential method within the generalized-gradient approximation.
- Direct method for calculating phonon dispersions under pressure.
- Comparison with experimental neutron scattering data.
Main Results:
- Weak discontinuities observed in pressure-volume and c/a-volume relations.
- Phonon dispersions calculated under pressure align with neutron scattering data.
- Substantial softening of acoustic phonon frequencies near the zone center at V/V0 ≈ 0.88 due to electronic topological transitions.
- Theoretical findings correlate with observed anomalies in the Lamb-Mössbauer factor.
Conclusions:
- The study provides a comprehensive theoretical analysis of hexagonal zinc under pressure.
- Electronic topological transitions significantly influence the lattice dynamics of zinc.
- The findings offer insights into the behavior of materials under extreme conditions.