Résumé:
We investigated the athermal high -pressure behavior of the elastic
properties of SrTiO3 (STO) up to 26GPa in cubic and tetragonal phases using the ab initio
pseudo-potential method. Our results for the cubic phase are in good agreement with
experiment and previous pseudo-potential calculations. There are no studies for the
tetragonal phase under high pressure available for comparison. Our calculations show
that the cubic-tetragonal phase occurs at 6 GPa. The elastic proprieties of STO are
strongly pressure dependent with instabilities near the phase transition pressure. STO is
more resistant to plastic deformation and the fracture in the cubic phase than in the
tetragonal phase
