IMF2017

Ferroelectric thin films have attracted considerable attention because they are used for non-volatile ferroelectric random access memories (FERAM). In particular, as the development of the aerospace industries, investigation on ferroelectric domain behavior of memory devices in exposed to high-energy radiation such as in space is required. In previous study, the ferroelectric thin films has been reported degradation behavior of polarization and dielectric properties by gamma-ray irradiation. Therefore, we investigated a change in the ferroelectric domain structure of epitaxial Pb(Zr_0.52Ti_0.48)O₃ (PZT) thin films by gamma-ray irradiation. Epitaxial PZT thin films were prepared on the SrRuO₃/SrTiO₃ (001) substrates by using a sol–gel method with a spin-coating process. The x-ray diffraction analysis show that fully c-axis oriented epitaxial PZT films were grown. The prepared epitaxial PZT thin films were subjected to gamma-ray radiation with various total doses. Piezoelectric force microscopy (PFM) is employed to study the ferroelectric domain structure in epitaxial PZT thin films. We have prepared 3 μm x 3 μm square patterns in PZT films, which areas were formed through the electrical poling with the cantilever by applying a + 5 V dc bias. By combining the perpendicular and in-plane piezoresponse data, we found that the ferroelectric domain structure is mainly described by one polarization directions. There patterns were investigated a change in the ferroelectric domain structure by repeated PFM measurements with various irradiation total doses. Based on these results, gamma-ray irradiation effects on ferroelectric domain structure in epitaxial PZT thin films will be discussed.