Mixed titania-lead oxide seed layers for PZT growth on Pt(111): a study on nucleation, texture and properties

Growth and properties of sputter in situ sputter deposited Pb(Z,Ti)O3 (PZT) thin films have been studied on (111)-textured Pt electrodes as a function of seed layers of the type (TiO2)x(PbO)y. The PZT process was run with a limited lead excess resulting in pyrochlore nucleation on bare Pt electrodes. When the electrode was covered with a dense seed layer, perovskite was obtained everywhere. Ti rich seed layers yielded (111)-textured PZT even for very thin seed layers. Pb rich seed layers nucleated as PbTiO3{100} and gave rise to (100)-textured PZT. In an intermediate zone, the major perovskite orientations (100), (110) and (111) have been found together with pyrochlore for a small seed layer thickness. In this zone, the seed layer nucleates in islands leaving bare Pt spots. The intermediate region is a transition region between (111) seeds and (100) seeds. The latter exhibit diverging critical sizes at a given critical flux ratio, leading to large nuclei and bare Pt.