Heterostructures consisting of a (100) LaA1O3 (LAO) or (111) SrTiO3 (STO) substrate, a SrRuO3 (SRO) metallic oxide bottom electrode, and a (1-x) Pb[Yb1/2Nb1/2]O3 - x PbTiO3 (PYbN-PT, x∼0.5 or 0.6) ferroelectric thin film were grown by the pulsed laser deposition process. The films were perovskite structured, with orientations that ranged from highly '001'pc-oriented PYbN-PT/SRO/LAO to highly '111'pc-oriented PYbN-PT/SRO/STO multi-layer systems. According to the crystal orientation, the ferroelectric and fatigue characteristics of such as-grown planar capacitors vary significantly. In particular, '001'pc-heteroepitaxial thin films result in fatigue-free capacitors up to 1011 cycles while '111'pc-oriented heterostructures exhibit a marked degradation of the switchable polarization by ac voltage cycling. These data agree with recent findings of fatigue anisotropy in relaxor ferroelectric-PbTiO3 single crystals. This orientation dependence may result from differences in the domain configuration and switching process.
All Science Journal Classification (ASJC) codes
- Materials Chemistry