Deactivation of pressure-induced amorphization in silicalite SiO2 by insertion of guest species.
The incorporation of carbon dioxide or argon stabilizes the structure of the microporous silica polymorph silicalite well beyond the stability range of tetrahedrally coordinated SiO(2) and, in fact, beyond even the metastability range of low-pressure silica polymorphs such as quartz and cristobalite at room temperature. The bulk modulus of silicalite strongly increases as a result of the incorporation of CO(2) or Ar and is equivalent to that of quartz. The insertion of these species deactivates the normal compression and pressure-induced amorphization mechanisms in this material, impeding the softening of low-energy vibrations, amorphization, and the eventual increase in silicon coordination up to at least 25 GPa.
Haines
Julien
J
Institut Charles Gerhardt Montpellier, UMR 5253 CNRS, Equipe C2M, Université Montpellier 2, Place E. Bataillon, cc1504, 34095 Montpellier cedex 5, France. jhaines@lpmc.univ-montp2.fr
Cambon
Olivier
O
Levelut
Claire
C
Santoro
Mario
M
Gorelli
Federico
F
Garbarino
Gaston
G