Phase transitions and electromechanical properties for barium titanate and lead titanate ferroelectric crystals under one-dimensional shock wave compression

Ferroelectric phase transitions and electromechanical properties of BaTiO₃ (BT) and PbTiO₃ (PT) crystals under one-dimensional shock wave compression were investigated using Landau-Ginzburg-Devonshire phenomenological approach. The results showed that the Curie temperature of both BT and PT increased with increasing pressure. Under highest shock wave compression, the orthorhombic phase was the stable state for BT, while no ferroelectric-ferroelectric phase transition was induced for PT. At room temperature, the electromechanical parameters for PT and BT were found to decrease with increasing one-dimensional compression, except for the dielectric susceptibility ε₂₂ and piezoelectric coefficient e₂₄ of tetragonal BT. The variations of dielectric and piezoelectric parameters were analyzed according to the elastic Gibbs free-energy.