Effects of Excess Bismuth Content in Precursor Solutions on Ferroelectric Properties of BiFeO_3 Thin Films Prepared by a Chemical Solution Deposition

摘要

Cr-substituted BiFeO_3 (BFCr) thin films prepared from precursor solutions with stoichiometric composition and various excess Bi contents ranged from 5 to 20 mol percent were fabricated on Pt/TiO_2/SiO_2/Si(100) substrates by a chemical solution deposition method, and the effects of excess Bi content in precursor solutions on the ferroelectric properties of the as-deposited BFCr thin films were studied. It was found that the BFCr thin film prepared from precursor solution with excess Bi content of 5 mol percent exhibited the best dielectric constant-frequency and polarization-electric field characteristics. In detail, its dielectric constant is 158 at frequency of 100 kHz and remnant polarization (P_r) value is 49 mu C/cm~2 at electric field of 600 kV/cm.