Shock-induced polymorphic transition in quartz, carbon, and boron nitride
A theory describing the polymorphism induced by shock waves in silicates, oxides, sulfides, and many inorganic solids is presented. Shock wave experiments conducted on these and other materials indicate that many transformations to high-pressure phases are triggered via the production of shear bands and, in some cases, formation of high-density amorphous phases. Shock states in the mixed phase regimes, of quartz, carbon, and boron nitride, are quantitatively described in terms of the properties of both their low- and high-pressure phases. Good agreement between the calculated results and measured Hugoniot data in the mixed phase regime is obtained. By fitting the pressures of the onset of the phase transition from graphite to diamond, and associating its triggering with crossing the extension of the metastable melting line of graphite, we obtain a similar shaped curve to the metastable melting line obtained by Bundy. Similarly, the transition from quartz to stishovite is associated with the metastable melting line of coesite. The present theory, when fit to the onset of the mixed phase regime of graphite like boron nitride transforming to cubic boron nitride Hugoniot, predicts the standard entropy for cubic BN to be 0.4-0.5 J/g K.
- Research Organization:
- California Inst. of Tech., Pasadena, CA (USA). Seismological Lab.
- OSTI ID:
- 6817521
- Report Number(s):
- AD-A-219614/5/XAB
- Resource Relation:
- Other Information: Pub. in Jnl. of Applied Physics, Vol. 67, No. 1, 217-224(1 Jan 1990)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BORON NITRIDES
PHASE TRANSFORMATIONS
CARBON
QUARTZ
AMORPHOUS STATE
DENSITY
DIAMONDS
ENTROPY
GRAPHITE
GRAPHS
HIGH PRESSURE
MELTING
METASTABLE STATES
MIXING
OXIDES
PRODUCTION
SHAPE
SHEAR PROPERTIES
SHOCK WAVES
SILICATES
SOLIDS
SULFIDES
BORON COMPOUNDS
CHALCOGENIDES
ELEMENTAL MINERALS
ELEMENTS
ENERGY LEVELS
EXCITED STATES
MECHANICAL PROPERTIES
MINERALS
NITRIDES
NITROGEN COMPOUNDS
NONMETALS
OXIDE MINERALS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PNICTIDES
SILICON COMPOUNDS
SILICON OXIDES
SULFUR COMPOUNDS
THERMODYNAMIC PROPERTIES
360602* - Other Materials- Structure & Phase Studies
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies