Structural and Optical Properties of Barium Strontium Titanate (Ba0.5Sr0.5TiO3) Thin Films

Ferroelectric Barium Strontium Titanate (Ba0.5Sr0.5TiO3) or BST thin films on quartz substrates have been prepared by using a modified sol gel processing technique. The starting materials are Barium 2-ethylhexanoate Ba[CH3(CH2)3CH(C2H5)CO2]2, Strontium 2-ethylhexanoate Sr[CH3(CH2)3CH(C2H5)CO2]2 and Titanium(IV) isopropoxide [TiOCH(CH3)2]4. The precursors except [TiOCH(CH3)2]4 were synthesized in the laboratory. Transparent and crack-free films were fabricated on quartz substrates by spin coating. The as-fired films were found to be amorphous, which crystallized to cubic phase after annealing at 550°C in air for 1 hr. In this paper we report the structural and optical properties of BST films prepared by the modified sol-gel process. Communicated by Prof. E. C. Subbarao