Influence of Crystal Structure on the Fatigue Properties of Pb 1− x La x (Zr y ′ , Ti z )O 3 Thin Films Prepared by Pulsed‐Laser Deposition Technique

Lead lanthanum zirconate titanate (Pb 1− x La x (Zr y ,Ti z )O 3 , PLZT) films containing [00 l ] preferentially oriented grains were produced successfully on YBa 2 Cu 3 O 7− x ‐coated (YBCOcoated) SrTiO 3 (STO) or YBCO/CeO 2 ‐coated silicon substrates; films containing randomly oriented grains were created on platinum‐coated silicon substrates. The latter possessed significantly inferior ferroelectric properties, a fact ascribed to the presence of a paraelectric phase (TiO 2 ) at the PLZT/platinum interface. On the other hand, the PLZT/YBCO/STO films exhibited better electrical properties than did the PLZT/YBCO/CeO 2 /Si films, and this phenomenon was attributed to better alignment of the grains in normal and in‐plane orientations. In terms of fatigue properties, the [00l] textured films that were deposited on YBCO/CeO 2 /Si substrates possessed substantially superior polarization‐switching‐cycle endurance versus the randomly oriented films grown on Pt(Ti)/Si substrates. Moreover, the tetragonal films behaved much more satisfactorily than did the rhombohedral PLZT films. The ferroelectric parameters of tetragonal PLZT films showed no significant degradation up to 10 9 polarization switching cycles, whereas the remnant polarization and coercive force of the rhombohedral PLZT films had already degraded to 80% of their initial values after 10 8 cycles.