Dielectric Properties of BaTiO3/SrTiO3 Oxide Superlattice

Abstract

BaTiO3 (BTO)/SrTiO3 (STO) artificial superlattices have been fabricated by pulsed laser deposition (PLD) on MgO (100). The stacking periodicity of the BTO/STO each layers in the superlattice was varied from one unit cell to 125 unit cell thickness. The dielectric constant and voltage tunability of the BTO/STO superlattice increased with decreasing the stacking periodicity of the BTO/STO within the critical thickness (∼ 20 nm). Dielectric constant and voltage tunability reached a maximum ∼1600 and 94 % at the stacking periodicity of BTO2 unit cell/STO2 unit cell. The size effect of the dielectric constant was significantly diminished by artificial oxide superlattice approach. Those dielectric properties were attributed to the lattice distortion of the superlattice.