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 Ti-rich 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.

Experimental research on performance parameters of a self-excited pulsed jet device

The self-excited pulsed jet is characteristically efficient and inexpensive. To develop an optimal pulsed jet, the structural and operating parameters affecting its peak hitting power were studied. The optimal range of cavity length and diameter, the areal ratio of the bottom and top nozzles, the bottom nozzle length, and the target distance and working pressure were all determined.