Phase Transitions and Disordering of CaSiO_3 upon Compression
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We performed high pressure Raman measurements on the chain silicates CaSiO<SUB>3</SUB> (wollastonite), MgSiO<SUB>3</SUB> (enstatite) and CaMgSiO<SUB>3</SUB> (diopside). All three systems undergo SiO<SUB>4</SUB> to SiO<SUB>6</SUB> coordination changes at pressures exceeding 40 GPa and this change may be mediated by a monoclinic C2/c crystal symmetry that the solids adopt before the transition. Observed disordering behaviour in CaSiO<SUB>3</SUB> may be due to steric constraints caused by the larger calcium ions occupying both countercation sites and internal strains due to the volume change associated with the four to sixfold coordination change.
- The Review of High Pressure Science and Technology
The Review of High Pressure Science and Technology 7, 359-361, 1998
The Japan Society of High Pressure Science and Technology