Effect of high hydrostatic pressure on the dielectric properties of BaTiO3 single crystals

The dielectric permittivity ϵ of BaTiO3 single crystals versus the temperature T at different hydrostatic pressure σ, and ϵ(σ) at different T, was measured. The highest σ achieved was 12 800 kg/cm2, between 22 °C and 180 °C. At σ < 3500 kg/cm2, the Curie point Tc decreases at a rate of −4.3 × 10−3 °C cm2/kg which ceases to be constant for σ > 3500 kg/cm2. The Curie‐Weiss temperature falls with growing σ. At higher σ, the Curie constant rises with growing σ. The ϵ(σ) graphs at constant T below 120 °C exhibit maxima related to an induced phase transition. Above 120 °C, ϵ decreases with growing σ. „Memory of pressure”︁ is observed on removal of high hydrostatic pressure.