Deviations from curie-weiss behavior of (ba0.06sr0.94)tio3 caused by high hydrostatic pressure due to quantum effects

Measurements of the dielectric constant of polycrystalline (Ba0.06Sr0.94)TiO3 under hydrostatic pressure p ≾ 0.7 GPa in the temperature range of (4.2 … 120) K show a critical exponent (CE) of the electric susceptibility dependent on temperature and pressure. Near the critical pressure, where the ferroelectric phase transition is vanishing, the CE is very sensitive to variations of pressure. At the critical pressure the CE reaches a maximum value because of quantum effects. An interpretation of this pressure dependence is given.