Enhancement of dielectric and ferroelectric properties of PbZrO3/PbTiO3 artificial superlattices

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 PZO/PTO artificial lattice exhibited a diffraction pattern characteristic of a superlattice structure, i.e., a main diffraction peak with satellite peaks. The electrical properties of the superlattices were investigated as a, function of the stacking period. The dielectric constant and remnant polarization improved on decreasing the stacking periodicity. The dielectric constant of the superlattice reached 800 at a stacking period of 1unit cell/1unit cell (PZO(1)/PTO1), which is larger than that of the single PZT solid-solution film. Moreover, the remnant polarization reached a, maximum, 2Pr = 38.7 muC/cm(2), at a 2-unit-cell stacking period, Progressive enhancement of dielectric constant and remnant polarization in artificial PZO/PTO superlattice was accompanied by expansion of the (100)-plane spacing on decreasing the stacking periodicity. These results suggest that the lattice strain developed in the PZO/PTO superlattice may have influence on dielectric constant and ferroelectric behavior.