Comparison of ferroelectric domain assemblages in Pb(Zr,Ti)O-3 thin films and bulk ceramics

Ferroelectric domain assemblages of bulk and thin film Pb(Zr,Ti)O-3 (PZT) c eramics are characterized as a function of grain size. Specifically, domain morphologies of chemically prepared, bulk PZT 95/5 (rhombohedral symmetry) ceramics are compared to tetragonally distorted perovskite PZT thin films of composition ranging from PZT 20/80 to PZT 53/47. Transmission electron m icroscopy (TEM), electron channel contrast imaging (ECCI) and backscattered electron Kikuchi patterns (BEKP) are the primary means of structural chara cterization. Domain morphologies in TEM foils, which have minimal mechanica l constraints, are to first order very similar to domain morphologies deter mined by ECCI of PZT thin films mechanically constrained to substrates and to those of bulk ceramics exhibiting internal stress. While quasistatic 90 degrees type domain patterns as a function of grain size are similar for bo th bulk and thin film ferroelectrics, 90 degrees domain dynamics are substa ntially different for PZT thin film and bulk materials. 90 degrees type dom ains are readily mobile under an applied electric field in large grain, bul k ceramics, but movement of these 90 degrees type domains is shown to be se verely limited in PZT thin films.