Optimization of synthesis of the solid solution, Pb(Zr1-xTix)O3 on a single substrate using a high-throughput modified molecular-beam epitaxy technique

Synthesis of Pb(Zr1-xTix)O-3 (PZT) on a single substrate using a high-throughput molecular-beam epitaxy technique was demonstrated. In situ synthesis of crystalline PZT at elevated substrate temperatures could not be achieved, as reevaporation of Pb (PbO) occurred and the partial pressure of O-2 was insufficient to prevent formation of a PbPtx phase during deposition. Instead, ex situ postdeposition annealing was performed on PZT deposited at room temperature. Dense single phase PZT was prepared with a compositional range of 0.1 > x > 0.9, for film thicknesses up to 800 nm. Transmission electron microscopy revealed the grain size increased from 50 nm to similar to 0.5 mu m with increasing Zr-concentration and became more columnar. Raman, x-ray diffraction. and scanning electron microscopy/energy dispersive spectroscopy results revealed a morphotropic phase boundary between rhombohedral and tetragonal phases occurred at x similar to 0.4 rather than at x = 0.47 in bulk ceramics. This was attributed to clamping arising from mismatch in thermal expansion between the film and substrate.