Crystallization of Precursor Micropatterns of Ferroelectric Bi₄Ti₃O₁₂ Fabricated by Electron Beam Scanning

Abstract

Crystallization of precursor micropatterns of ferroelectric Bi 4 Ti 3 O 12 fabricated by electron beam scanning was investigated in comparison with that of thin films. Precursor solutions were prepared by mixing bismuth and titanium octylates with various Bi : Ti molar ratios. Single-phase Bi 4 Ti 3 O 12 thin films were formed by spin-coating a solution containing Bi and Ti atoms at a molar ratio of 5.2 : 3.0 and successive heat treatment. It was possible to control orientation of the Bi 4 Ti 3 O 12 thin films by changing the sintering temperature. Bi 4 Ti 3 O 12 thin films consisting of platelike crystals with predominantly c -axis orientation were obtained by sintering at 800°C. Precursor micropatterns were fabricated by scanning an electron beam on metal octylate films and development with toluene. They were crystallized into single-phase Bi 4 Ti 3 O 12 by sintering at 800°C. However, the Bi 4 Ti 3 O 12 micropatterns consisted of small grains, unlike the large platelike crystals in thin films. There was a clear difference in crystallization between the thin films and the micropatterns.