Effect of TiO_X nucleation layer on crystallization of Bi₄Ti₃O₁₂ films

Abstract

Crystalline Bi4Ti3O12 films were fabricated using a chemical solution deposition route. The spin solution was prepared with bismuth acetate and titanium isopropoxide dissolved in a mixture of acetic acid and 2-methoxyethanol. The effect of a titanium oxide buffer layer and Bi4Ti3O12 seed layers on Bi4Ti3O12 film crystallization was studied. The titanium oxide buffer layer and the Bi4Ti3O12 seed layer reduced grain size and grain size distribution. Less preferential c axis orientation was observed on TiOx than on Pt. Ferroelectric hysteresis loops were measured on Bi4Ti3O12 films with thickness1 ranging from 70 to 180 nm at 1-16 volts with remanent polarizations up to 14 μC/cm2. Remanent polarizations of 3-4 μC/cm2 at 4 volts were measured for Bi4Ti3O12 films on Pt with all the layers annealed all at once with no titanium oxide buffer layers or Bi4Ti3O12 seed layers.