Superlattices of PbZrO3 and PbTiO3 prepared by multi-ion-beam sputtering

Abstract

Artificial superlattices consisting of antiferroelectric PbZrO3 (PZO) and ferroelectric PbTiO3 (PTO) have been fabricated by a multi-ion-beam sputtering technique. The epitaxial PZO and PTO layers were sequentially grown on (100)Pt/MgO substrates at a low substrate temperature of 415 °C with a periodicity from 5 to 100 perovskite unit cells. X-ray diffraction studies revealed the superlattice structures with a-axis oriented PTO layers on a-axis oriented PZO layers. The dielectric and ferroelectric properties of the superlattice films were enhanced with increasing periodicity.

Dielectric properties of ferroelectric thin films with surface transition layers

“…The Hamiltonian of the TIM [5][6][7][8][9][10] is (1) where Ω i is the transverse field (for H-bond ferroelectrics, it represents the proton tunneling between the two equilibrium positions on the H bonds), and are the x and z components of a spin operator at site i (the thermal average of is related to the polarization), J ij is the two-spin exchange interaction constant between site i and site j, and the sum runs over all sites. E is the applied electric field and μ is the dipole moment.…”

“…However, surface and size effects are two important phenomena observed in ferroelectric thin films which have been known since early 1950's and still have many problems to be answered. In recent years the finite-size and surface effects on the phase transition temperature, spontaneous polarization, and dielectric susceptibility of ferroelectric thin films have been extensively studied both experimentally [1][2][3][4] and theoretically [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The Dielectric properties have been reported for Pb(Zr, Ti) O 3 (PZT) [21,22], PbTiO 3 [23], BaTiO 3 [24], and (Ba, Sr)TiO 3 (BST) [25,26] thin films by many groups.…”

Hysteresis loops of a bilayer superlattice

“…Recently, because of the advances in fabricating multilayer structures, ferroelectric superlattices have been extensively studied. For example, BaTiO 3 /SrTiO 3 and PbTiO 3 /PbZrO 3 superlattices with perovskitetype structure have been grown by molecular beam epitaxy and multi-ion-beam sputtering techniques [1][2][3]. Also, (Sr, Ca)TiO 3 /(Ba, Sr)TiO 3 superlattices have been formed using a pulsed laser ablation method [4,5].…”

Dielectric properties of a ferroelectric superlattice with two alternating layers

“…Recently, because of the advances in fabricating multilayer structures, ferroelectric superlattices have been extensively studied. For example, BaTiO 3 /SrTiO 3 and PbTiO 3 /PbZrO 3 superlattices with perovskite-type structure have been grown by molecular beam epitaxy and multi-ion-beam sputtering techniques [1][2][3]. Also, (Sr,Ca)TiO 3 /(Ba,Sr)TiO 3 superlattice has been formed using a pulsed laser ablation method [4,5].…”