Electrical properties and poling of BaTiO3 thin films

Abstract

Dielectric and ferroelectric properties were measured for both highly a-axis textured and randomly oriented BaTiO3 thin films deposited on Pt coated MgO substrates via metal-organic chemical-vapor deposition. Dielectric constants on the order of ε∼10 and an absence of ferroelectric hysteresis were generally observed for the as-deposited films. Upon applying an electric field exceeding a threshold value of ∼50–100 kV/cm across the film, both the dielectric constant and the ferroelectric hystersis were enhanced significantly as a result of poling. The dielectric constant increased to ε∼100, and the spontaneous polarization of the a-axis textured film reached Ps≥15 μC/cm2. The measured dielectric and ferroelectric properties of the BaTiO3 thin films depended on the microstructure of the films.