Abstract: The degradation behavior of SrBi2 Ta2O9 (SBT) thin filras annealed in forming gas (5%H2+95%N2) was investigated. The ferroelectric remnant polarization Pr of SBT had a severe decrease in the containing H2 atmosphere at 400℃. SEM results showed that Bi could be reduced from SBT thin films for the effect of H2. The reduction role increased with a rise of annealing temperature. SBT thin films lost their ferroeb ctric- ity when the annealing temperature was above 450℃. It implied that the degradation of Pr value or the disappearance of ferroelectricity in SBT thin films had the relationship with the reductive amounts of Bi in SBT. H2 played an important role in degradation of ferroelectric SBT thin films. This role could be attributed to its strong reduction activity during forming gas annealing.

Key words: ferroelectric, SrBi2 Ta2 O9 thin film, forming gas annealing