Phase transitions in [001]-oriented morphotropic PbZr0.52Ti0.48O3 thin film deposited onto SrTiO3-buffered Si substrate

An 85 nm-thick morphotropic PbZr0.52Ti0.48O3 (PZT) film grown epitaxially and [001]-oriented onto a SrTiO3-buffered Si-wafer is investigated using temperature dependent X-ray diffraction. Two phase transitions, at Trt ∼ 500 K and Tc ∼ 685 K, are evidenced and are attributed to structural phase transitions from monoclinic-like to tetragonal-like phase and from tetragonal to paraelectric phase, respectively. The stronger upper shift of Trt value with respect to the bulk one and the weakly affected Tc (Tc bulk ∼ 665 K) are explained assuming misfit strain changes when crossing Trt. This finding opens new perspectives for piezoelectric PZT films in harsh applications.