IMF2017

Nucleation at the Pt surface plays an important role in formation of CSD PZT films. The nucleation of (111) perovskite (Pe) grains occurs directly on the Pt (111) surface. The presence of TiO₂ or PbO on the Pt surface stimulates growth of Pe grains with (100) orientation. As a result, CSD PZT films on Pt demonstrate a mixed (111) and (100) Pe orientation. Pb-reach or Ti-reach seed layers are commonly used to enhance (100) orientation that is important, for example, for MEMS applications due to higher piezoelectric coefficient value. On the other hand (111) orientation may be preferable for FeRAM applications due to less elastic stress during domains switching. New crystallization technique for produce of PZT films with high (111) orientation is proposed in this work. It is based on deposition of layers with different Pb-excess in precursor solution. The first crystallization step (deposition of a seed layer) is performed at a low Pb excess (0 - 5 wt %) to form highly oriented Pe (111) grains. The next crystallization step is performed with a 30 wt % excess of Pb to prevent formation of pyrochlore particles and accelerate the growth of Pe grains. An effect of the low-Pb-excess seed layer on the film texture, hysteresis loops, grain size, polarization dependences of the transient currents, and local current distribution are discussed. It is shown, that in the case when first crystallization step proceeds at a low Pb content condition, Pe (111) texture is sufficiently enhances with complete suppression of others orientations.