Structural and electrical properties of homologous Srm−3Bi4TimO3m+3 (m=3, 4, 5, and 6) thin films

Abstract

Polycrystalline thin films of Bi-layered ${\mathrm{Sr}}_{\text{m−3}}{\mathrm{Bi}}_4{\mathrm{Ti}}_m{\mathrm{O}}_{\text{3m+3}}$ (referred to as BTO for $\text{m=3}$ and ${\mathrm{SBTi}}_m$ for $\text{m=4,5,}$ and 6 respectively) were fabricated on Pt-coated silicon substrates by pulsed laser deposition. Structures were characterized by x-ray diffraction, atomic force microscopy, and scanning electron microscopy. Electric properties were investigated systematically. It was revealed that the remnant polarization $P_r$ depended greatly on the parity of m. This dependence was well explained by using a rotating oxygen octahedra model along the a axis. The superior fatigue properties of ${\mathrm{SBTi}}_m$ $\text{(m=4,5,6)}$ over BTO films were discussed in detail. The high dielectric constants and low dissipation factors of the films were demonstrated.