Pressure induced elastic softening in framework aluminosilicate- albite (NaAlSi₃O₈).

ABSTRACT: Albite (NaAlSi₃O₈) is an aluminosilicate mineral. Its crystal structure consists of 3-D framework of Al and Si tetrahedral units. We have used Density Functional Theory to investigate the high-pressure behavior of the crystal structure and how it affects the elasticity of albite. Our results indicate elastic softening between 6-8 GPa. This is observed in all the individual elastic stiffness components. Our analysis indicates that the softening is due to the response of the three-dimensional tetrahedral framework, in particular by the pressure dependent changes in the tetrahedral tilts. At pressure <6 GPa, the PAW-GGA can be described by a Birch-Murnaghan equation of state with  = 687.4 ų,  = 51.7 GPa, and  = 4.7. The shear modulus and its pressure derivati

SUBMITTER: Mookherjee M 

PROVIDER: S-EPMC5062091 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature