The effect of Pb stiochiometry on switching behavior of Pt/lead zirconate titanate/Pt ferroelectric capacitors

A promising approach to control Pb stoichiometry during crystallization of sol-gel-derived lead zirconate titanate (PZT) layers is presented. Pyrolyzed layers were encapsulated in a quartz ampoule containing PbZrO3 powder and crystallized in a lamp furnace. For moderate heating rates, the PbO ambient created by the powder resulted in a pronounced sharpening of the preferential (111) texture, while the remanent polarisation Pr increased by 50% compared to nonencapsulated samples. A significant reduction of the coercive field was seen for layers crystallized under PbO ambient, reflected in a lowering of the switching voltage by 0.5 V compared to standard hotplate crystallized films. The results highlighted the key role of Pb stoichiometry control for further lowering the switching voltage of PZT films.