Dielectric Properties of PbZrO3/PbTiO3 Artificial Superlattices Grown by Pulsed Laser Deposition

PbZrO3 (PZO)/PbTiO3 (PTO) artificial superlattices have been grown on La0.5Sr0.5CoO3 (LSCO) (100)/MgO (100) substrate by pulsed laser deposition with various stacking periods from 1 to 100 unit-cells. The electrical properties of the superlattices were investigated as a function of the stacking period. The dielectric constant and remnant polarization were improved with decreasing the stacking periodicity. The dielectric constant of the superlattice reached 800 at a stacking period of 1unit-cell/1unit-cell (PZO1/PTO1), which is larger than that of the single PZT solid solution film grown at a relative high temperature. Moreover, the remnant polarization reached a maximum, 2Pr = 38.7 μ C/cm2 at 2 unit cell-stacking period. As the total thickness of the superlattices with a 2 unit cell-stacking period (PZO2/PTO2) decreased, the corresponding dielectric constant decreased. As long as the dielectric constant is concerned, the finite size effect was observed in the artificial PZO/PTO superlattice with a thickness down to 20 nm.