Pulsed laser deposition of epitaxial non-doped PbTiO3 thin films from Pbo-TiO2 mosaic targets

PbTiO3 (PTO) suffers from difficulty in preparing high-density robust bulk ceramics, which in turn has been a bottleneck in thin films growth with physical vapor deposition (PVD) methods. In the present work, we prepared non-doped PTO thin films by a pulsed laser deposition (PLD) method with either a single PTO target or a mosaic target consisting of PbO and TiO2 pie-shaped pieces. On the PTO single target, laser irradiation caused selective ablation of Pb, resulting in Tirich cone-shaped pillar structure on the surface, whereas the irradiated surface of PbO and TiO2 pieces was smoother. Epitaxial PTO films deposited on SrTiO3 (001) substrates from the pie-chart targets with PbO:TiO2 areal ratio from 3:5 to 5:3 resulted in composition, crystallinity, flatness, and ferroelectric properties almost independent of the areal ratio. The averaged composition of each film was close to stoichiometric, suggesting a compositional self-control mechanism. For growing epitaxial and high-quality non-doped PTO films, a PbO-TiO2 pie-chart target is advantageous in easiness of handling and stable surface structure.This research was supported by Spanish Ministry of Competitiveness (projects MAT2016-77100-C2-1-P and PID2019-108573GB-C21) and the AGAUR agency (project 2017SGR). ICN2 is funded by the CERCA programme/Generalitat de Catalunya and by the Severo Ochoa programme of the Spanish Ministry of Economy, Industry and Competitiveness (MINECO, Grant No. SEV-2017-0706)