| 1. |
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| 2. |
- Li, S., et al.
(författare)
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Crystallographic structures of PbWO4
- 2003
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Ingår i: High Pressure Research. - : Informa UK Limited. - 0895-7959 .- 1477-2299. ; 23:3, s. 343-347
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Tidskriftsartikel (refereegranskat)
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| 3. |
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| 4. |
- Luo, W., et al.
(författare)
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Structural phase transitions in brookite-type TiO2 under high pressure
- 2005
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Ingår i: Solid State Communications. - : Elsevier BV. - 0038-1098 .- 1879-2766. ; 133:1, s. 49-53
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Tidskriftsartikel (refereegranskat)abstract
- We have studied polycrystalline brookite TiO2 using energy-dispersive X-ray diffraction at pressures up to 27.8 GPa and derived an ambient-pressure bulk modulus of 255 GPa using Birch-Murnaghan's equations of state with a fixed value of 4 as its first derivative. The transition from brookite-type to baddeleyite-type was observed to start at 15.8 GPa and finished at 22.8 GPa. Upon decompression, the alpha-PbO2 structure appeared at 3.5 GPa and the baddeleyite-type structure remained down to 1.6 GPa. the lowest pressure in the present work.
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| 5. |
- Wang, Y., et al.
(författare)
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Accurate quantum mechanical treatment of phonon instability : body-centred cubic zirconium
- 2002
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 14:43, s. L695-L701
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Tidskriftsartikel (refereegranskat)abstract
- The T-1 N point and (omega point phonon anomalies for body-centred cubic (bcc) Zr are studied using an approach which goes beyond the traditional quasi-harmonic approximation and perturbation theory. We are able to reproduce, for the first time, the anomalous phonon behaviour in bcc Zr.
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| 6. |
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| 7. |
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| 8. |
- Wang, Y., et al.
(författare)
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Mean-field potential approach to the quasiharmonic theory of solids
- 2004
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Ingår i: International Journal of Quantum Chemistry. - : Wiley. - 0020-7608 .- 1097-461X. ; 96:5, s. 501-506
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Tidskriftsartikel (refereegranskat)abstract
- Adopting the quasiharmonic approximation, a newly developed classical mean-field potential (MFP) approach is extended to the quantum case. Two new Debye temperature expressions, which are in accordance with the thermodynamic theory of Dugdale and MacDonald and with the free volume theory, respectively, are derived in addition to the well-known expression of Slater. The Gruneisen law is now implied explicitly in the Debye temperature expression, and therefore no additional conditions for the Gruneisen constant are needed for realistic thermodynamic calculations. The thermal expansion and specific heat of Na, Cu, Mo, Ta, and Th have been calculated from 10 K up to the melting point.
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| 9. |
- Wang, Y., et al.
(författare)
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Melting of iron and other metals at earth's core conditions : A simplified computational approach
- 2002
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 65:1
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Tidskriftsartikel (refereegranskat)abstract
- In order to Study melting of metals' at high pressure, we propose a different method which can be thought of as a generalization of the well-known Lindemann law. One essential interesting feature is that neither the Debye temperature nor the Gruneisen coefficient are used in the theory. We find that the method based on first-principles calculations can be used to model the pressure dependence of the melting properties of metals very well, predictions of the melting along the principal Hugoniot are calculated for Cu and Ta. In the case of Fe, the melting temperature is calculated at geophysically interesting pressures.
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| 10. |
- Wang, Y., et al.
(författare)
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Model for phase coexistence in phase transitions
- 2004
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Ingår i: International Journal of Quantum Chemistry. - : Wiley. - 0020-7608 .- 1097-461X. ; 97:6, s. 961-965
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Tidskriftsartikel (refereegranskat)abstract
- We propose a general model for describing the phenomena of phase coexistence in relation to pressure induced phase transformations by means of the T-P distribution in statistical thermodynamics. Using the well-known B1-B2 transition in NaCl as a prototype, we demonstrate how phase coexistence gives rise to the changes in the bulk modulus and the equation-of-state across the transition.
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